*B 2flt 
 
ON 
 
 WARMING AND VENTILATION, 
 
RUDIMENTARY TRE 
 
 WAKMING AND VENTILATION; 
 
 BEING A CONCISE EXPOSITION OF THE 
 
 GENERAL PRINCIPLES OF THE ART 
 
 WARMING AND VENTILATING DOMESTIC AND PUBLIC 
 BUILDINGS, MINES, LIGHTHOUSES, SHIPS, &c. 
 
 BY 
 
 CHAELES TOMLINSON. 
 
 WITH AN APPENDIX, 
 BRINGING THE SUBJECT DOWN TO THE PRESENT TIME. 
 
 LONDON: 
 JOHN WEALE, 59, HIGH HOLBOKN. 
 
 1858. 
 
LONDON : 
 BRADBtlBY AND EVANS, PRINTERS, WHI1 KFRIARS. 
 
PREFACE. 
 
 THE art of warming and ventilating buildings in a manner 
 most conducive to health, convenience, and economy, has 
 been discussed during many years with an earnestness 
 which has increased with the increasing interest of the 
 public. The scientific Chemist, the popular Lecturer, the 
 Engineer, and we may hope in some cases the Architect 
 and the Builder have not failed to convince their readers 
 and hearers how and why it is that constant supplies of 
 pure air are even more necessary to health, than the arti- 
 ficial warmth by which the rigours of our uncertain climate 
 are mitigated. More than one-half the diseases which 
 afflict humanity have been referred to the breathing of 
 impure air, and a large proportion of our ailments certainly 
 originate in our imperfect methods of warming. 
 
 Admitting, then, the importance of the subject, it seems 
 to be equally important to furnish the public with accurate 
 information thereon, in a cheap and popular form. The 
 art of warming and ventilating depends on natural prin- 
 ciples of great beauty and generality, which have been 
 clearly made out by the scientific chemistry of the last 
 three quarters of a century. These principles are expounded 
 at some length in the following little work; but as their 
 application involves a description of other men's inventions, 
 
 M510948 
 
VI PREFACE. 
 
 and a compilation from other men's books, we have made 
 free use (under due acknowledgment) of the labours of 
 writers who have preceded us on the subject. Most of 
 these books have long since passed out of notice ; but Mr. 
 Hood's work still retains its hold on the public mind. 
 Though professing to be merely a Treatise on Warming 
 Buildings by Hot Water, it is really a scientific memoir of 
 great value, dealing with most of the conditions on which 
 the application of artificial heat depends, and treated in so 
 lucid and exact a manner as to inspire confidence in the 
 author. This work, which is now in its Fifth Edition, may 
 be considered as occupying a permanent place in our 
 technological literature. We have repeatedly acknowledged 
 our obligations to it in the following pages, and we beg to 
 repeat here the recommendation contained in the note to 
 p. 135. " The writer takes this opportunity of expressing 
 his obligations to this valuable work, to which he refers 
 the reader who desires to master the subject on which it 
 treats." The assent of Mr. Hood to the use which has 
 been made of his book increases the writer's obligations 
 to him. 
 
CONTENTS. 
 
 INTRODUCTION. On the Physical and Chemical Principles con- 
 cerned in the Art of Warming and Ventilation . 
 
 PAET I. 
 
 CHAPTER I. On the Methods of Warming Houses by means of 
 Open Fire-Places, &c., before and after the Introduction of 
 Chimneys 47 
 
 CHAPTER II. On the Methods of Warming Buildings by means 
 
 of Close Stoves and Hot-Air Apparatus .... 95 
 
 CHAPTER III. On the Warming of Buildings by means of Steam 
 
 and Hot Water . 121 
 
 PAET II. 
 
 CHAPTER I. On the General Principles of Ventilation ; and the 
 Method of Ventilating Buildings, Ships, &c., by Spontaneous 
 Action and by Mechanical Contrivances . . . .156 
 
 CHAPTER II. On the Ventilation of Buildings, Ships, Mines, 
 
 Lighthouses, &c., by means of Artificial Heat . . . . 200 
 
 CHAPTER III. On the Methods of Ventilating Buildings by 
 means of Hot Water, Low and High Pressure Steam, and by 
 Condensed Air 236 
 
 CONCLUSION. On the great importance of attention to Ventilation 255 
 
 APPENDIX. 
 
 On the Principal Inventions and Improvements that have been 
 made in the Art of Warming and Ventilating between the 
 years 1850 and 1858 261 
 
WARMING & VENTILATION. 
 
 INTRODUCTION. 
 
 ON THE PHYSICAL AND CHEMICAL PRINCIPLES CONCERNED IN THE 
 ART OF WARMING AND VENTILATION. 
 
 AN inquiry into the constitution and uses of our atmosphere 
 in the economy of nature and art, is calculated to promote a 
 solemn feeling of admiration and gratitude. This wonderful 
 creation encloses within its capacious curves, like a vast dome, 
 the widely extended kingdoms of nature, to which it ministers 
 materials for growth, health, and enjoyment, and by its trans- 
 parency reveals to intelligent beings a glimpse of other crea- 
 tions beyond its limits. At one time, it stands in simple 
 grandeur as a vault of tender blue, displaying the glorious sun 
 and the landscape smiling beneath ; at another time, its sur- 
 face is chequered with fleecy clouds, "the beauteous sem- 
 blance of a flock at rest," or alpine heights of more than 
 silvery brightness, or huge piled up masses, dark and frown- 
 ing ; all contributing to form wondrous variety and beauty in 
 the aerial scenery, and giving to the landscape below the ever 
 varying charms of light and shade. Again, the blue of this 
 splendid ceiling becomes deeper and deeper, and bright golden 
 points shine out here and there, increasing in number until the 
 whole surface appears as if richly studded with gems. 
 
 If these great and glorious sights were of rare occurrence, or 
 could only be witnessed from a few chosen spots on the 
 earth's surface, they would stimulate our curiosity, and we 
 should eagerly hasten to those spots, or read the descriptions 
 and gaze at the pictures which travellers and artists had pre- 
 
 B 
 
2 GENERAL VIEW OF 
 
 pared for us. Their common occurrence, however, causes 
 them to be viewed with indifference; but there are also many- 
 hidden wonders connected with the atmosphere equal in 
 beauty to those which appeal directly to the eye, but 
 requiring study for their due appreciation. The atmosphere 
 is a scene of incessant restless activity. The heat of the 
 tropical sun upon the earth sets the air in motion, rarefies and 
 causes it to ascend; meanwhile the air from cooler regions 
 rushes towards the equator to supply the vacuum, performing 
 various useful offices on its way. Here it is the trade wind or 
 the monsoon ; there it is the sea or the land breeze ; in 
 a third place, it is the hill and valley breeze, all giving 
 health and refreshment to places which otherwise might be 
 uninhabitable. Meanwhile the heated ascending air of the 
 equator proceeds on its useful mission in the direction of the 
 poles, forming an upper current, descending in some places 
 and mitigating the cold of temperate regions, as the under 
 current tempers the heat of tropical climes. The heat, too, 
 which gives force and activity to these aerial currents or vast 
 natural ventilators, also raises the waters of the ocean and 
 charges the air with moisture ; this moisture ascends and 
 forms clouds, those busy and active water-carriers which 
 traverse the unobstructed regions of the sky, and pour down 
 their treasures on the city and the plain, and on the desert 
 where no water is, filling the mountain cisterns, whence gush 
 out the springs and rivers ; and these descend in a meandering 
 course, and diffuse beauty and blessing on the lower lands long 
 after the rain cloud has been dissolved. It is the resistance of 
 the atmosphere that causes the rain to come down in gentle 
 drops, and thus gradually to diffuse its refreshing influence, 
 instead of falling in torrents and cataracts, as it otherwise 
 would, without the retarding and separating influence of the 
 air. It is the atmosphere which dispenses the white fleecy 
 flakes of snow to the temperate regions, whereby the earth is 
 covered and protected from the chilling influence of a low 
 temperature; the air, too, is the region of mists and fogs, 
 
THE ATMOSPHERE. 3 
 
 which bring moisture in a still more gradual manner ; a cold 
 current of air blowing over a warmer stratum of air, and cooling 
 it, thereby rendering its moisture visible ; or, after sun-set, the 
 river may be warmer than the air, and the escaping vapour 
 condense into large rolling masses. But we especially notice 
 the beneficial effects of differences of temperature between the 
 air and the earth in the formation of dew ; the moisture which 
 the heat of the day had exhaled from the earth is deposited 
 when a cloudless sky allows the earth to radiate its heat into 
 space, and to cool down below the temperature of the air; the 
 refreshing moisture is then condensed upon vegetation and 
 upon surfaces where it is most needed. 
 
 Not only are we able to trace in the atmosphere those great 
 and regular motions which bring about an interchange 
 between the air of the equator and that of either pole, but 
 there are other motions, apparently more fitful and irregular, 
 in the winds, which blow from all points of the compass, and 
 tend perpetually to restore the equilibrium of heat and 
 moisture. 
 
 How wonderful, too, is the action of the atmosphere on light. 
 By its means the sun's rays are diffused, and their influence 
 extended from the sunshine to the shade. Were it not for 
 the atmosphere, the sun would shine in an intensely dark sky, 
 and no object would be visible unless the solar rays fell directly 
 upon it. Sun-set would be a sudden transition from light to 
 darkness ; and sun-rise a painful change from intense darkness 
 to intense light. But under the present wise and providential 
 arrangement, the transition from day to night is calm and 
 peaceful; the sun departs in splendour, like a monarch attended 
 by a gorgeous court, leaving a mild and subdued scene of 
 beauty behind ; the soothing influences of evening gradually 
 steal upon us, and new scenes of wonder and beauty gradually 
 become unfolded. After some hours of peace and rest, the 
 portals of the eastern sky slowly open, and one rosy messenger 
 after another ascends to announce the advent of the king of 
 day. 
 
 B 2 
 
GENERAL VIEW OF 
 
 In addition to these complicated duties which the atmos- 
 phere has to perform, there are yet others still more 
 wonderful. A large number of the operations of nature are, 
 as it were, daguerreotyped in the air in such a manner, as to 
 convey to sentient and intelligent creatures information of 
 what is going on. The murmuring of waters, the tinkling of 
 rills, the whispering of winds, the sound of the forest in the 
 blast, the rush of the cascade, the roar of the ocean, and the 
 roll of the thunder, are only certain motions among material 
 bodies, which impress their own peculiar characters on the 
 air, and form what are called sounds. Sounds are of so 
 numerous and, at the same time, of so distinctive a character, 
 that a large portion of every language is appropriated to their 
 precise description. Thus, to define a few of the sounds 
 emitted by certain animals, we speak of the lowing of 
 cattle, the bleating of sheep, the cawing of rooks, the cooing 
 of pigeons, the hissing of snakes, and many others. These 
 sounds, expressive of certain wants and motions, feelings and 
 sympathies, have, doubtless, an intelligent meaning among the 
 respective species of animals to which they apply ; but both 
 so,und and its perception are alike dependent on the atmos- 
 phere. The phenomena of sound and of hearing, however, 
 obtain their most perfect and exalted development in articu- 
 late speech, by which intelligent and responsible creatures are 
 enabled to shape air into words, those swift and winged 
 messengers by which we express our wants and feelings, by 
 which we advise, instruct, or admonish others, share in their 
 joys, their sorrows and affections ; a glorious and also a 
 fearful gift, since every idle word that man shall speak he 
 will have to give account of at the day of judgment. Inferior 
 only to articulate speech is the language of music, which, 
 like the beauty produced by form and colour, is an invention 
 calculated to promote the happiness of man. 
 
 The uses of the air in the arts of life are innumerable. It 
 is the cheapest and most effectual prime mover; we have 
 merely to supply the tools, the machinery, and the work to be 
 
THE ATMOSPHERE. O 
 
 done, and it will labour with untiring activity. It wafts our 
 ships over every sea, turns our mills, raises water in our 
 pumps, accompanies the diver in the diving bell, bears up the 
 balloon, feeds our furnaces : but here we come to a distinct 
 series of valuable offices performed by the atmosphere, 
 if possible, even more extensive and important than those 
 already referred to. The chemical history of the atmosphere 
 is even more wonderful than the physical,* and will now 
 require, for the object of the present essay, a few details. 
 
 The atmosphere is composed essentially of two gases, in a 
 state of mechanical mixture, named oxygen and nitrogen. In 
 its pure state, oxygen is chiefly remarkable for its energetic 
 properties in promoting combustion, decomposition, and 
 various chemical changes. A taper, with a mere spark of 
 fire in the wick, will, when plunged into oxygen, burst into 
 flame and burn brilliantly; iron wire, made red-hot at one 
 extremity, will burn away with the greatest ease in this gas. 
 An animal, in an atmosphere of pure oxygen, suffers from 
 excess of vital action ; its pulses throb with increased rapidity 
 and vigour, the vital spark, as it were, bursts into flame, and 
 destroys the animal. Nitrogen (or, as it is sometimes called, 
 azote,) is as inert in its properties as oxygen is active. It 
 supports neither life nor combustion, and its principal use in 
 the atmosphere seems to be to dilute the oxygen, and to 
 subdue the wonderful energy of this vigorous element to the 
 endless number of useful purposes which it has to perform in 
 the economy of nature. The proportions in which these two 
 gaseous bodies are mingled, are very unequal ; every atom or 
 particle of oxygen in the atmosphere is accompanied by four 
 atoms or particles of nitrogen ; or, in other words, if we take 
 a measure of any capacity, divided into five equal parts, and 
 decant into it four parts of nitrogen and one part of oxygen, 
 we get a mixture identical in all respects with pure atmos- 
 pheric air. 
 
 * The physical properties of the atmosphere are investigated in 
 Rudimentary Pneumatics. 
 
6 COMBUSTION AND ITS RESULTS. 
 
 In the great chemical operations of nature which are de- 
 pendent on the atmosphere, oxygen passes through yarious 
 mutations, and enters into new combinations, which form the 
 basis of grand and wonderful contrivances. Some of the 
 most important of these operations depend on the process of 
 combustion, of which the following is a simple illustration : 
 A piece of wax taper (Fig. 1), fixed in the 
 centre of a cork, is lighted and floated on the 
 surface of water in a shallow dish ; if this 
 be enclosed within a bell glass, the mouth 
 of which dips into the water and rests on 
 the dish, the air of the glass will be cut off 
 from any communication with the external 
 atmosphere. The flame of the taper will 
 immediately diminish, and in a few seconds 
 be extinguished. On examining the air left in the glass, it 
 will be found incapable of supporting animal life or combus- 
 tion ; four- fifths of the original bulk of air is still nitrogen, 
 and this is apparently unchanged ; the remaining fifth is no 
 longer oxygen, but a compound of oxygen with the carbon 
 and hydrogen of the flame oxygen and carbon producing 
 carbonic acid, and oxygen and hydrogen producing water, 
 which, in the form of vapour, condenses on the inner surface 
 of the glass. 
 
 Now the product of combustion, called carbonic acid, is 
 incapable of supporting life and combustion, and thus re- 
 sembles nitrogen. But there are these differences between 
 them : nitrogen is a little lighter than its own bulk of atmos- 
 pheric air ; carbonic acid is considerably heavier ; nitrogen is 
 an elementary or simple substance, that is, one which has 
 never yet been resolved into two or more dissimilar parts ; 
 carbonic acid, on the contrary, is a compound capable of being 
 separated or decomposed into carbon or charcoal, and oxygen. 
 Moreover, pure nitrogen, shaken up in a bottle, with a little 
 lime water, produces no effect; carbonic acid renders it turbid, 
 by combining with the lime and rendering it insoluble ; nitro- 
 
CARBON AND HYDROGEN. 7 
 
 gen is scarcely absorbed by water, but water absorbs its own 
 volume of carbonic acid; nitrogen has no taste or smell, 
 carbonic acid has a sharp taste and an acid reaction. Hence, 
 it will be seen, that these two bodies, which have the common 
 property of extinguishing life and preventing combustion, are 
 marked by characteristic differences. 
 
 Some idea may be formed of the enormous demands on the 
 oxygen of the atmosphere for supporting combustion, from the 
 fact, that a single iron furnace burns or consumes, in the course 
 of twenty-four hours, not less than three hundred and ten tons 
 weight of atmospheric air, or as much as would be required 
 for the respiration of two hundred thousand human beings 
 within the same period. 
 
 Carbon, which forms the solid basis of most fuel, and in a 
 minutely divided state renders flame luminous, is a simple sub- 
 stance, and exists in nature under a variety of forms. Its 
 purest form is the diamond, as is proved by the formation of 
 carbonic acid only, when it is burnt in pure oxygen. Charcoal and 
 coke are other well known forms of carbon, the one obtained 
 from wood and the other from coal ; coal is a compound of 
 carbon, hydrogen, nitrogen, and oxygen, with a mineral and 
 earthy residue. Wax, tallow, &c., are compounds of carbon, 
 hydrogen, and oxygen. 
 
 Hydrogen, which is the source of all common flame, is the 
 lightest substance that has ever been weighed : it is more than 
 fourteen times lighter than its own bulk of atmospheric air at 
 the same temperature ; it supports neither life nor combustion. 
 Alighted taper plunged into it is extinguished, but the hydrogen 
 itself takes fire and burns at the mouth of the jar, where it is 
 in contact with the oxygen of the air, with which it unites and 
 forms water. One volume of oxygen combines with two of 
 hydrogen to form water ; or by weight, one grain of hydrogen 
 unites with eight grains of oxygen, and as the hydrogen is 
 sixteen times lighter than its own bulk of oxygen, it follows 
 that one grain of hydrogen will occupy twice the bulk of eight 
 grains of oxygen. Pure hydrogen burns with scarcely any light ; 
 
8 CHEMICAL COMBINATIONS. 
 
 in the flame of our lamps, candles, gas lights, &c., the minutely 
 divided carbon, in rising up through the flame, becomes white 
 hot, and presents innumerable luminous points ; at the exterior 
 of the flame the oxygen of the atmosphere seizes the minute 
 atoms of carbon as they escape, and, by combining with them, 
 forms invisible carbonic acid. A cold substance, such as a 
 piece of glass or metal, held in a flame for a moment will con- 
 dense a portion of the carbon in a minutely divided state. If 
 a lamp have a deficient supply of air, it will smoke, that is, a 
 portion of the carbon of the flame will escape without com- 
 bining with the oxygen of the air. Lamp black is formed by 
 burning oil in a close chamber with a deficient supply of air. 
 
 Hydrogen unites with nitrogen to form ammonia, three 
 volumes of hydrogen being required to one of nitrogen. This 
 substance is pungent and acrid, but when diluted with air is 
 an agreeable stimulent. It is very soluble in water, which at 
 the temperature 50, takes up 670 times its bulk of the gas. 
 Ammonia is an alkali, and combines readily with acids, pro- 
 ducing an important class of ammoniacal salts. 
 
 Nitrogen and oxygen combine to form nitric acid, one part 
 of nitrogen uniting with five parts of oxygen. Not only are 
 these numbers different from those which represent the com- 
 position of the atmosphere, but the mode of combination is 
 different. The oxygen and nitrogen of the atmosphere are 
 mixed mechanically, just as a portion of fine sand diffused 
 through water may be said to mix with it without combining. 
 In either case, the bodies preserve their own peculiar properties j 
 or the properties of the compound form a mean between those 
 of its component elements. But in a chemical combination 
 between two bodies, a third body is formed, whose properties 
 need not, and seldom do, resemble those of the component 
 elements. Thus sulphur and oxygen combine chemically to 
 produce sulphurous or sulphuric acid, substances whose pro- 
 perties are quite different from those of the sulphur and 
 oxygen which produce them ; the sulphurous has also very 
 different properties from the sulphuric. So with nitric acid, 
 
ENLARGED VIEW OF COMBUSTION. 
 
 this compound has none of the properties of the constituents of 
 the atmosphere, but a new set of properties peculiar to itself. 
 This powerful acid may be formed artificially in various ways, 
 but only one need here be mentioned. By passing a succession 
 of electric sparks through a mixture of oxygen and nitrogen, 
 this acid is formed ; so also, during a thunder storm, the 
 lightning striking through vast masses of atmospheric air, 
 produces nitric acid, which, combining with ammonia, also 
 formed in the atmosphere, descends with the rain upon the earth 
 in the form of nitrate of ammonia. 
 
 Now the object for which these details have been brought 
 forward, is to enable the reader to take an enlarged view of the 
 process of combustion, for this, in fact, constitutes the chief 
 means by which nature accomplishes her annual cycle. An 
 accurate knowledge of the homely processes of warming and 
 ventilation depends upon a clear insight into the principles of 
 combustion, and it is only an oft repeated truism, that our 
 useful arts become more efficient in practice, more economical, 
 and more conducive to our happiness, in proportion to our 
 knowledge of the principles upon which they depend. Now, 
 according to the common acceptation of the term, combustion 
 is the rapid union of a combustible with a supporter of com- 
 bustion, whereby new compounds are formed, heat and light 
 accompanying the formation. Thus a piece of iron wire or of 
 phosphorus ignited and plunged into a jar of oxygen gas burns 
 vividly, the iron falling in molten drops amid showers of scin- 
 tillations, and the phosphorus emitting a vivid flood of painful 
 light. In this process, the oxygen and the iron unite to form a 
 new substance, oxide of iron ; the oxygen and the phosphorus 
 also form a new substance, phosphorous acid. If, however, the 
 iron be exposed long enough to the atmosphere, the oxygen 
 will combine with it in precisely the same manner, and form 
 oxide of iron ; months or even years may be required for the 
 completion of the process which in the jar of oxygen was 
 accomplished in a few seconds ; but the result is the same. 
 The same amount of heat is evolved by the combination of the 
 
 B5 
 
10 IDENTITY OP 
 
 oxygen and the iron during the slow process of rusting, as in 
 the rapid process of burning. So also with the phosphorus. 
 A piece of this substance exposed to the air combines with the 
 same amount of oxygen, and evolves precisely as much heat 
 during the time that it slowly wastes away, and produces the 
 same weight of acid as it would do if burnt in a jar of oxygen. 
 
 Now it must be evident, that if a process, rapidly brought 
 about in one case and slowly in another, produce the same 
 results, we do not add to our knowledge by associating 
 different names and different trains of thought with the one 
 as compared with the other; on the contrary, we disembarrass the 
 subject by considering the processes as identical ; whether the 
 combustion be rapid or slow, it is still combustion. Undoubt- 
 edly there are cases where slow combustion is not possible. 
 A piece of coal and the oxygen necessary to its combustion 
 may remain in contact for centuries without undergoing any 
 change; but the moment a spark of fire is introduced, they 
 begin to combine and soon disappear, with all the more 
 obvious phenomena of combustion. In such a case, all we 
 can say is, that a high temperature is necessary for the 
 combination ; but this case does not disturb the view we are 
 endeavouring to impress upon the reader, that combustion may 
 be a very slow process as well as a very rapid one. 
 
 Let us take another case of combustion. If a portion of 
 the solid food of animals be placed in a red hot platinum 
 crucible, it will burn away ; its carbon will unite with oxygen 
 from the air and form carbonic acid ; its hydrogen will unite 
 with oxygen from the air and form water ; its nitrogen may 
 escape free, or it may unite with a portion of its hydrogen, and 
 form ammonia j and in this way all the gaseous volatile products 
 will be expelled from the crucible, leaving behind only a small 
 portion of ash, which consists of salts, some of which are 
 soluble in water and others insoluble in that fluid. 
 
 Now, in a chemical point of view, the living animal frame 
 is a real apparatus for combustion ; it is a vital furnace, in 
 which the carbon supplied by the fuel, which we call food, 
 
RESPIRATION AND COMBUSTION. 11 
 
 is burnt, and, combining with oxygen, escapes by the lungs 
 and the skin into the atmosphere, under the form of carbonic 
 acid. In this apparatus also the hydrogen of food is burnt, 
 and uniting with oxygen, escapes as aqueous vapour ; the 
 nitrogen of the air, as taken into the lungs, is again exhaled 
 by respiration, but the nitrogen and soluble mineral portions 
 of the food are rejected under the form of oxide of ammo- 
 nium in the urine ; the insoluble mineral portions of the 
 food are rejected in the form of solid excrement. 
 
 Now every portion of food which a person of mature age 
 takes into his system, is thus dispersed from day to day. In 
 infancy and youth a portion is retained to form materials for 
 growth ; in old age, the individual loses more than he receives, 
 and, consequently, wastes slowly away. But, in each case, the 
 natural process is similar to the artificial one represented in 
 the heated platinum crucible. We cannot, therefore, resist 
 the evidence that the combustion of food, whether in the 
 animal or in the crucible, is one and the same process j the 
 only difference being, that in the crucible the heat is intense 
 and the process rapid j in the animal, the heat is moderate 
 and the process comparatively slow. That which is called 
 animal heat (98 Fahr.), is in fact the heat of combustion, 
 and the object of the domestic processes of warming and 
 ventilation is to enable the animal to maintain this heat, and 
 to convey away the guseous products of combustion as fast as 
 they are formed. The soluble and insoluble products of com- 
 bustion are conveyed away by other natural means ; and it 
 will be our duty hereafter to show, that it is as unwise to 
 neglect the means for clearing off our gaseous excrements, as 
 it would be insane and unnatural to attempt to retain those of 
 another kind. 
 
 Another proof of the identity of the two processes is that 
 nature disposes of the products of combustion in precisely 
 the same manner, whether derived from ordinary combustion 
 or animal respiration. The vegetable kingdom is the grand 
 laboratory wherein these products of combustion are decom- 
 
12 USES OF THE VEGETABLE KINGDOM. 
 
 posed and elaborated into new combinations. Plants inhale 
 or absorb carbonic acid, decompose it, retain the carbon as 
 materials for growth, and return the oxygen back to the 
 atmosphere ; plants absorb water or aqueous vapour, decom- 
 pose it, retain its hydrogen, and also return back the oxygen 
 to the atmosphere ; plants sometimes take nitrogen directly 
 from the air, and sometimes indirectly from the oxide of am- 
 monium or from nitric acid. Thus it will be seen that the 
 chemical function of plants is directly the reverse of that of 
 animals the animal kingdom constituting an immense appa- 
 ratus for combustion ; the vegetable kingdom an equally 
 grand apparatus for reduction, in which reduced carbonic acid 
 yields carbon, reduced water its hydrogen, and in which also 
 reduced oxide of ammonium and nitric acid yield their am- 
 monia or their nitrogen. The organic matter which constitutes 
 the food of animals is destroyed by them, and rendered for the 
 most part inorganic ; this, in its turn, becomes the aliment of 
 plants, the materials with which plants elaborate organic com- 
 pounds, the atmosphere serving as the means of communication 
 between the two kingdoms. Organic vegetable substances 
 pass ready formed into herbivorous animals, which destroy a 
 portion of them, and appropriate the remainder as materials 
 for growth. From herbivorous animals these organic matters 
 pass ready formed into the carnivorous, who destroy or retain 
 some of them, according to their wants. The herbivorous 
 animals are slaughtered for the use of the carnivorous, and 
 when these, in their turn, cease to live, they decompose, and 
 the atmosphere again takes up, in various ways and by various 
 processes, the materials of which they were composed. 
 
 The great stimulus which gives motion to the wonderful 
 machinery of the vegetable world is solar light. Under its 
 influence, the carbonic acid yields its carbon, the water its 
 hydrogen, the ammonia its nitrogen. It is not for the purpose 
 of purifying the air that plants are especially necessary to 
 animals. Their great use is to furnish a never failing supply 
 of organic matter, ready prepared for assimilation, in short, 
 
AMOUNT OP CARBON FROM RESPIRATION. 13 
 
 with fuel, which animals can burn for their own use. The 
 purification of the air by vegetation is a remote service ; the 
 other service is so immediate, that if it were to fail us during 
 a single year, the earth would be depopulated.* The mean 
 amount of carbonic acid in the atmosphere is scarcely one 
 volume in 2,000, which is a surprisingly small quantity, when 
 we consider how numerous and productive are the sources of this 
 gas. Volcanoes, fires, animals, fermentation, and decay, are 
 constantly producing it, nor will the quantity given off by a 
 single individual appear insignificant, when it is stated that 
 Sir Humphry Davy found that he required, for the purposes of 
 respiration, during the 24 hours, 45,504 cubic inches of oxygen, 
 weighing 15,751 grains, and producing 31,680 cubic inches of 
 carbonic acid, weighing 17,811 grains, or 4,853 grains of carbon. 
 These numbers vary with different individuals, and also in the 
 same individual at different periods of the day j according to 
 Dr. Prout, the maximum quantity of carbonic acid is given off 
 about noon, up to which period it gradually increases from the 
 beginning of twilight; and afternoon, it as gradually diminishes 
 until evening, and is at its minimum during the night. It 
 appears, from the mean of a large number of observations, that 
 the average quantity of carbon evolved from the lungs 
 amounts to 130 grains per hour, or 3,120 grains in 24 hours, 
 which is rather more than 7 ounces daily. This calculation 
 does not take into account the carbonic acid evolved by 
 cutaneous respiration. The quantity of oxygen consumed in 
 respiration varies also with the state of exertion or repose of 
 the individual. According to an observation of Lavoisier, the 
 consumption of oxygen in the two states was as 32 to 14. The 
 
 * The chemical relations between the three great kingdoms of nature 
 ire stated at greater length in our Essay on the Application of 
 Chemistry to Agriculture, appended to Professor Fownes' Rudimentary 
 Chemistry ; but the reader who desires to pursue the subject further, is 
 referred to Liebig's Chemistry in its Application to Agriculture, 
 Professor Johnstone's Elements of Agricultural Chemistry and 
 Geology, and also to a Lecture by M. Dumas, on the Chemical Statics 
 of Organized Beings. 
 
14 INJURIOUS EFFECTS 
 
 quantity of vapour given off by the lungs has also been 
 variously stated, but the average is supposed to be about 3 grains 
 per minute ; according to Thenard, the amount of vapour given 
 off by the skin varies from 9 to 26 grains per minute. 
 
 In the process of respiration, a full grown man draws into 
 his chest about 20 cubic inches of air ; only one-fifth of this is 
 oxygen, and nearly one half of this oxygen is converted into 
 carbonic acid. Now allowing fifteen inspirations per minute 
 for a man, he will vitiate about 300 cubic inches, or nearly 
 one-sixth of a cubic foot of atmospheric air, and this, by 
 mingling as it escapes with several times as much, renders at 
 least two cubic feet of air unfit for respiration. Now the 
 removal of this impure air, and the bringing in of a constant 
 fresh supply, have been provided for by nature in the most 
 perfect manner, and it is by our ill- contrived artificial 
 arrangements that the provision is defeated. The expired 
 and vitiated air, as it leaves the chest, is heated to very near 
 the temperature of the body, viz. 98, and being expanded by 
 the heat, is specifically lighter than the surrounding air at any 
 ordinary temperature ; it therefore ascends and escapes to a 
 higher level, by the colder air pushing it up, as it does a 
 balloon. The place of this heated air is constantly supplied 
 by the colder and denser air closing in on all sides. In the 
 open air the process is perfect, because there is nothing to 
 prevent the escape of the vitiated air j but in a close apart- 
 ment, the hot air, rising up to the ceiling, is prevented from 
 escaping; and gradually accumulating and becoming cooler, it 
 descends and mingles with the fresh air, which occupies the 
 lower level. We thus have to inhale an atmosphere which 
 every moment becomes more and more impure and unfit for 
 respiration; and the impurities become increased much more 
 rapidly by night when lamps and candles or gas are burning, 
 for flame is a rapid consumer of oxygen. Under these circum- 
 stances, our only chance of escape from suffocation is in the 
 defective workmanship of the house-carpenter ; the crevices 
 in the window frames and doors allow the foul air a partial 
 
OF BADLY VENTILATED ROOMS. 15 
 
 exit, as may be proved by holding the flame of a candle near 
 the top of a closed door, in a hot room ; it will be seen that 
 the flame is powerfully drawn towards the door in the direc- 
 tion of the outgoing current j and on holding the flame near 
 the bottom of the door, it will be blown away from the door, 
 shewing the direction of the entering current. If we stop 
 up these crevices, by putting list round the windows and doors, 
 so as to make them fit accurately, we only increase the evil. 
 The first effect is, that the fire will not draw for want of sufficient 
 draught ; if the inmates can put up with a dull fire and a smoky 
 atmosphere, they soon become restless and uncomfortable 
 young people get fretful and peevish, their elders irritable, respi- 
 ration becomes impeded, a tight band appears to be drawn round 
 the forehead, which some invisible hand seems to be drawing 
 tighter and tighter every moment ; the eyeballs ache and 
 throb, a sense of languor succeeds to fits of restless impatience, 
 yawning becomes general, for yawning is nothing more than 
 an effort of nature to get more air into the lungs ; under these 
 circumstances the announcement of tea is a welcome sound, 
 the opening and shutting of the door necessary to its prepara- 
 tion give a vent to the foul air, the stimulus of the meal 
 mitigates the suffering for a time, but before the hour of rest, 
 the same causes of discomfort have been again in active 
 operation, and the family party retires for the night indisposed 
 and out of humour. 
 
 But in the bed room, the inmates are not free from the \ 
 malignant influence. The closed doors, the curtained bed, and \ 
 the well closed windows, are sentinels which jealously guard 
 against the approach of fresh air. The unconscious sleepers 
 at each respiration vitiate a portion of air which, in obedience 
 to the law of nature rises to the ceiling, and would escape, if 
 the means of escape were provided ; but, in the absence of 
 this, it soon shakes off those serial wings, which would have 
 carried it away, and becoming cooler and denser, it descends, 
 and again enters the lungs of the sleepers, who unconsciously 
 inhale the poison. When the room has become surcharged 
 
16 EFFECTS OF VITIATED AIR. 
 
 with foul air, so that a portion must escape, then, and not till 
 then, does it begin to escape up the chimney. Hence many 
 persons very properly object to sleep in a room which is 
 unprovided with a chimney ; but it is evident that such a ven- 
 tilator is situated too low down to be of much service. If 
 there be no chimney in the room, a portion of the foul air 
 escapes by forcing its way out of some of the cracks and 
 crevices which serve to admit the fresh air. 
 
 That this sketch is not overdrawn, must be evident to any one 
 who, after an early morning's walk, may have returned directly 
 from the fresh morning air into the bed room which he had left 
 closely shut up an hour before. What is more disgusting than 
 the odour of a bed room in the morning "? Why is it that so 
 many persons get up without feeling refreshment from their 
 sleep 1 Why do so many persons pass sleepless nights 1 The 
 answer to these and many other similar questions may be 
 frequently found in defective ventilation. How much disease 
 and misery arises from this cause it would be difficult to state 
 with any approach to accuracy, because the causes of misery 
 are very complicated. Among the poor, the want of sufficient 
 nourishment, neglect of temperance and cleanliness, and ex- 
 cessive labour, all act with aggravating effect upon want of 
 ventilation and drainage. Among the middle classes, mental 
 anxiety, overtasked powers, insufficient out-door exercise, are 
 also aggravating causes j but there is a similar want of atten- 
 tion to ventilation and drainage. The rich suffer least, because 
 they pass much of their time in the pure air of the country, 
 and are relieved from a good deal of anxiety, by being inde- 
 pendent in circumstances ; their rooms are also larger and less 
 crowded than those of the other classes ; but still there is a 
 neglect of ventilation, and they often breathe a poisonous 
 atmosphere for hours together in the crowded and heated ball 
 room, the theatre, and the fashionable assembly; so that faint- 
 ing, headache and sickness, are the not uncommon results. 
 
 A poisonous atmosphere ! The expression will not be found 
 too strong when we examine the ingredients of the air of an 
 
EFFECTS OF CARBONIC ACID. 17 
 
 unventilated room. The products of combustion, whether 
 they be those of the respiration of human beings, or the 
 burning of artificial light, consist of 1, carbonic acid ; 2, 
 nitrogen ; 3, vapour of water, mingled with various animal 
 products of a very offensive nature. Gas also often con- 
 tains a minute portion of sulphuretted hydrogen which 
 escapes, and a minute portion of the gas itself (carburetted 
 hydrogen) also escapes unburnt. 
 
 Carbonic acid gas is a deadly poison. If we attempt to 
 inhale it by putting the face over the edge of a beer vat, the 
 nostrils and throat are irritated so strongly, that the glottis 
 closes, and inspiration becomes impossible. In its pure state, 
 then, it is impossible to breathe carbonic acid gas ; but when 
 this gas is largely diluted with air, it can be breathed, and the 
 symptoms resemble those of apoplexy. Professor Christison 
 quotes a case related by M. Chomel of Paris, of a labourer, 
 who was suddenly let down to the bottom of a well containing 
 carbonic acid diluted with air, where he remained three- 
 quarters of an hour. On being drawn up, he was first affected 
 with violent and irregular convulsions of the whole body, 
 accompanied by perfect insensibility ; fits of spasm, like 
 tetanus, then came on. During the second day, these symp- 
 toms went off, and he continued afterwards to be affected with 
 dumbness. It is especially to be noted, that contrary to 
 general popular belief, these effects may be produced in situa- 
 tions where the air is not sufficiently impure to extinguish the 
 flame of a candle ; nor does the lurking danger display itself 
 to the sense of taste or of smell. 
 
 The danger of using charcoal as a fuel will be noticed further 
 on ; but we may here remark, that the proportion of carbonic 
 acid necessary to produce a poisonous atmosphere is very 
 small; so much so, that in attempts at suicide by burning 
 charcoal in an open room, the people who have entered the 
 apartment have found the air quite respirable, and the choffer 
 burning, although the person they sought was in a state of 
 deep coma, from having been long exposed to the noxious 
 influence. 
 
18 NITROGEN AND ANIMAL EFFLUVIA. 
 
 Now as no person would consent habitually to swallow a 
 small portion of liquid poison, knowing it to be such, though 
 diluted with a very large portion of pure water, so it is equally 
 unwise to consent habitually to inhale a small portion of 
 gaseous poison, knowing it to be such, though diluted with a 
 very large portion of pure air; and yet this is what the 
 majority of persons actually do who occupy apartments un- 
 provided with proper ventilating apparatus. 
 
 Nitrogen gas, which constitutes four- fifths of our atmos- 
 phere, is not, like carbonic acid gas, a poison. Its properties 
 are altogether inert ', it will not support respiration nor com- 
 bustion, simply from the absence of oxygen. An animal 
 plunged into an atmosphere of nitrogen would die, simply 
 because this gas is incapable of oxygenising the blood, A 
 flame is extinguished in this gas, simply because there is no 
 affinity between it and the incandescent hydrogen and 
 carbon. 
 
 The vapour given off by the lungs and the skin is charged 
 with offensive animal effluvia, which greatly promote the con- 
 tamination of the air of a crowded apartment. Dr. Faraday 
 expressed his opinion to a parliamentary committee in 1835, 
 on the subject of ventilation, that " Air feels unpleasant in 
 the breathing cavities, including the mouth and nostrils, not 
 merely from the absence of oxygen, the presence of carbonic 
 acid, or the elevation of temperature, but from other causes, 
 depending on matters which are communicated to it by the 
 human being. I think that an individual may find a decided 
 difference in his feelings when making part of a large company, 
 from what he does when one of a small number of persons, and 
 yet the thermometer give the same indication. When I am 
 one of a large number of persons, I feel an oppressive sensa- 
 tion of closeness, notwithstanding the temperature may be 
 about 60 or 65, which I do not feel in a small company at 
 the same temperature, and which I cannot refer altogether to 
 the absorption of oxygen, or the evolution of carbonic acid, and 
 probably depends upon the effluvia from the many present ; 
 but with me, it is much diminished by a lowering of the tern- 
 
EFFECTS OF SULPHURETTED HYDROGEN. 19 
 
 perature, and the sensations become much more like those 
 occurring in a small company. The object of a good system 
 of ventilation is to remove the effects of such air." 
 
 The effects of air, vitiated by animal effluvia, is evident in 
 the diseases of the lower animals when crowded together in 
 confined places. The glanders of horses, the pip of fowls, and 
 a peculiar disease in sheep, all arise from this cause ', and it 
 is stated that, for some years past, the English nation has been 
 saved ,10,000 a year, in consequence of the army veterinary 
 surgeons adopting a simple plan for the ventilation of the 
 cavalry stables. 
 
 Our systems of artificial illumination have even a greater 
 deteriorating effect upon the air of an apartment than the 
 respiration of human beings. The leakage of a gas pipe, or 
 the imperfect combustion of the gas itself, in an apartment, 
 would cause the inmates to inhale a portion of the gas. 
 Sir Humphry Davy found, that when he breathed a mixture 
 of two parts air and three of carburetted hydrogen, he was 
 attacked with giddiness, headache, and transient weakness of 
 the limbs ; but common gas is often contaminated with 
 sulphuretted hydrogen, as the blackening of the white painted 
 wainscoting of rooms proves, in spite of the purifying processes 
 adopted at the gas works. This gas is the most deleterious of 
 all the aerial poisons. It has been found by experiment, that 
 air, impregnated with a 1,500th part of the gas, kills a bird in 
 a short space of time ; and that with about twice that propor- 
 tion, or an 800th, it will soon kill a dog. This gas is emitted 
 by cesspools and sewers, and has been a frequent cause of 
 death when breathed in a state of concentration. "The 
 individual becomes suddenly weak and insensible, falls down, 
 and either expires immediately, or if he is fortunate enough 
 to be quickly extricated, he may revive in no long time, the 
 belly remaining tense and full for an hour or upwards, and 
 recovery being preceded by vomiting and hawking of bloody 
 froth." When the noxious emanations are less concentrated, 
 the symptoms are still very alarming ; and in the dilute form, 
 
20 THE EFFECTS OF 
 
 as in the emanations from the gully holes of the sewers 
 of London, persons inhaling them have often been attacked 
 with sickness, colic, imperfectly defined pains in the chest, and 
 lethargy. 
 
 The emanations arising from the imperfect or slow combus- 
 tion of oil and tallow are most injurious to health. The 
 vapour of a smoky lamp, if disengaged in small quantities, 
 excites intense head-ache. The fumes of the burning snuif of 
 a candle are probably of the same nature, and are very poison- 
 ous, and every one must have remarked their penetrating 
 nature ; they fill the room the moment a candle is blown out, 
 and their disgusting odour pervades the whole house in a 
 a very short time. Dr. Christison quotes a case in which they 
 proved fatal ; a party of ironsmiths, who were carousing 
 on a festival day at Leipzig, amused themselves with 
 plaguing a boy, who was asleep in a corner of the room, by 
 holding under his nose the smoke of a candle just extin- 
 guished; at first he was roused a little each time, but when the 
 amusement had been continued for half an hour, he began to 
 breathe laboriously, was then attacked with incessant epileptic 
 convulsions, and died on the third day. 
 
 In addition to all these contaminating agents, carbonic acid, 
 nitrogen, animal effluvia, carburetted and sulphuretted hy- 
 drogen, &c., to which the air of an un ventilated apartment 
 is liable, there is yet another cause of injury to health in the 
 disturbed electrical condition of vitiated air. This is a subject 
 on which science has hitherto thrown no light. All that we 
 can do is to record the fact, that pure air, such as is fit for 
 respiration, is positively electric, while the air, which has 
 become impure, and consequently unfit for respiration, is 
 negatively electric. 
 
 The effects of breathing an impure air have frequently been 
 insisted upon by medical and other writers. In the evidence 
 taken before the Committee of the House of Commons, on the 
 health of towns, in the year 1840, the medical witnesses stated, 
 that scrofulous diseases were a common result of bad ventila- 
 
BREATHING IMPURE AIR. 21 
 
 tion,* and that, in the case of silk weavers, who pass their 
 lives in a more close and confined air than almost any other 
 class of persons, their children are peculiarly subject to 
 scrofula, and softening of the bones. Dr. Arnott stated, that 
 an individual, the offspring of persons successively living in 
 bad air, will have a constitution decidedly different from a 
 man who is born of a race that has inhabited the country for a 
 long time ; that the race would, to a certain extent, continue 
 degenerating. Defective ventilation deadens both the mental 
 and bodily energies, it leaves its mark upon the person, so that 
 we can distinguish the inhabitants of a town from those of the 
 country. This witness, in alluding to the want of knowledge 
 among all classes on the subject of ventilation, states that he 
 had heard at the Zoological Gardens of a class of animals where 
 fifty out of sixty were killed in a month, from putting them 
 into a house which had no opening in it but a few inches in the 
 floor. " It was like putting them under an extinguisher ; and 
 this was supposed to be done upon scientific principles." 
 
 Some of the details in this report of diseases, consequent on 
 the habitual breathing of air, vitiated by a number of human 
 beings, crowded together in a badly drained and ill-ventilated 
 part of London, are so frightful, that it is impossible to quote 
 them here. No doubt these details refer to extreme cases 
 among the poor and destitute ; but no one will contend that 
 the science and legislation of the day should be exerted only 
 
 * Mr. Carmichael, in his Essay on the Nature of Scrofula, 
 accounts for the extreme prevalence of the disease in the Dublin House 
 of Industry, at the time he wrote (1810), by mentioning that in one 
 ward of moderate height, 60 feet by 18, there were 38 beds, each con- 
 taining three children, or more than 100 in all. The matron remarked, 
 that there is no enduring the air of this apartment when the doors are 
 first thrown open in the morning ; and that it is in vain to raise any 
 of the windows, as those children who happened to be inconvenienced 
 by the cold, close them as soon as they have an opportunity. The air 
 they breathe in the day is little better; many are confined to the 
 apartments they sleep in, or crowded to the number of several hundred 
 in the school room. 
 
22 DEFECTIVE VENTILATION 
 
 for those who have influence to command, or means to purchase 
 their aid. Every one who has knowledge or wealth at his dis- 
 posal, is bound to exert it as much for the benefit of his 
 ignorant and poorer brethren as for his own pleasure and 
 profit. There is not only a moral law requiring us to do so, 
 but there is also a natural law, and both have this distin- 
 guishing proof of their divine origin; they are self acting; they 
 confer the reward of obedience, and inflict the penalty of trans- 
 gression, with a precision and certainty which find no parallel 
 in mere human laws and institutions. The fevers and con- 
 tagious diseases, arising from our neglect of the poor, find their 
 way into our own dwellings ; the miasma of our courts and 
 alleys enters our lungs, and casts us on a bed of sickness. If, 
 through the mercy of God, we are permitted to rise again, 
 ought we not to practise the lesson which the penalty has been 
 seeking to convey to us ? 
 
 But not only are our dwelling houses badly ventilated, but 
 those buildings on which the architect has lavished all his art 
 and skill are, for the most part, entirely destitute of special 
 means for ventilation ; and are so constructed, as to render 
 the application of such means extremely difficult, or even 
 impossible. Such a contrivance seldom enters the mind 
 of the architect. A building capable of holding from 
 800 to 1000 persons, whether it be a church, a lecture room, 
 an assembly room, or a concert room, is, in consequence of this 
 neglect, the too frequent scene of much painful suffering. 
 When such a room is crowded, and the meeting lasts for some 
 hours, especially in winter, the consequences are sufficiently 
 marked ; "either such a multitude must be subjected to all the 
 evils of a contaminated and unwholesome atmosphere, or they 
 must be partially relieved by opening the windows, and allow- 
 ing a continued stream of cold air to pour down upon the 
 heated bodies of those who are near them, till the latter are 
 thoroughly chilled, and, perhaps, fatal illness is induced ; and 
 unfortunately, even at such a price, the relief is only partial, 
 for the windows being all on one side of the room, and not 
 
IN PUBLIC BUILDINGS, ETC. 23 
 
 extending much above half way to the ceiling, complete ven- 
 tilation is impracticable. This neglect is glaringly the result 
 of ignorance, and could never have happened, had either the 
 architects or their employers known the laws of the human 
 constitution."* 
 
 The same intelligent writer remarks, that in churches 
 fainting and hysterics occur more frequently in the afternoon 
 than in the morning, because the air is then at its maximum 
 of vitiation. Indeed, in a crowded church, the effects of de- 
 ficient air are visible in the expression of the features of every 
 one present " either a relaxed sallow paleness of the surface, 
 or the hectic flush of fever, is observable, and, as the necessary 
 accompaniment, a sensation of mental and bodily lassitude is 
 felt, which is immediately relieved by getting into the open 
 air." Some persons, however, do not find this relief; the 
 headache often lasts for hours, and ends in a bilious or nervous 
 attack. 
 
 Our school rooms are also sadly defective in respect of ven- 
 tilation, and we have known cases where, with all the windows 
 open, a proper supply of air could not be introduced into the 
 crowded apartment. When the weather did not allow of open 
 windows, the atmosphere of the room was most loathsome 
 to a visitor entering it from the fresh air. All the inmates com- 
 plained of a sensation of fulness and tightness in the forehead, 
 and headache more or less acute. Command of temper on the 
 part of the teachers, and mental progress on the part of the 
 pupils, are of course next to impossible under such circum- 
 stances. The writer would appeal to the experience of 
 teachers in general, whether the slow comprehension and 
 listlessness of children in school, who are sharp and clever in 
 the playground, may not be traceable in a great measure to 
 the vitiated air which they are compelled to inhale ? 
 
 In curious contrast to the defective arrangements of most of 
 our public buildings, with respect to ventilation, are our public 
 
 * Dr. Andrew Combe's Principles of Physiology. 
 
24 DEFECTIVE VENTILATION. 
 
 theatres. These are, for the most part, tolerably well venti- 
 lated, or at least some attempt is made to procure ventilation, 
 and the managers do not fail to parade the fact in their play- 
 bills at the opening of the season. They are practical men ; 
 they know that for some years past the attention of the public 
 has been directed to the subject of ventilation, and that a 
 studious attention to the comfort of the house is as likely to 
 bring people to it as attractive performances. They know, too, 
 that people are more likely to enjoy and applaud the business 
 of the stage when they can breathe freely, than when the 
 head is aching and the senses are steeped in the drowsiness of 
 a mephitic atmosphere. Some of the methods of ventilating 
 theatres are clever and efficient, as will be noticed hereafter, 
 and could easily be applied to those far more important build- 
 ings, the church and the lecture room. 
 
 The traveller, in pursuit of health, business, or pleasure, 
 is everywhere exposed to inconvenience and suffering from 
 want of ventilation. In our coaches, railway carriages, and 
 steam-boats, there are no means, or very inefficient ones, for 
 ventilation. Many of our readers will probably be able to 
 call to mind their nights of suffering in the heavy coaches of 
 twenty years ago, or less. The writer has frequently travelled 
 inside the Salisbury coach in winter, which left London at 
 5 P.M., and arrived in Salisbury next morning at about 7 A.M., 
 thus performing a journey of 85 miles in 14 hours; such a 
 journey, with six inside (and the writer has sometimes 
 formed one of eight), with windows closed at the special 
 request of some lady or gentleman, who seemed capable of 
 breathing without the usual supply of fresh air, was a 
 protracted torture not to be voluntarily endured in these 
 days.* Yet it must be confessed that our railway carriages are 
 
 * In illustration of this part of our subject, we venture to relate the 
 following anecdote, which, as far as we know, has never before appeared 
 in print : Some years ago, an elderly gentleman, well known in the 
 west of England, was travelling in the night coach from London to 
 Salisbury, when he requested permission to have one of the windows 
 
IN CARRIAGES, SHIPS, ETC. 25 
 
 not much better when the windows are closed and the tra- 
 vellers are numerous. A second class carriage often contains 
 from twenty-four to thirty, and even forty persons, and the 
 air, under such circumstances, is intolerable. The first class 
 carriages are better, because there is less crowding, but even 
 these are seldom provided with efficient means for the escape 
 of the vitiated air. The sleeping cabins of our steam-boats, 
 though fitted up with general attention to comfort, are entirely 
 without any special contrivances for ventilation. We have 
 travelled more than once from London to Hamburg, and 
 have slept, or endeavoured to sleep, two nights in the cabin of 
 one of the steam company's magnificent boats. The eager- 
 ness with which we have exchanged the foetid air of the 
 cabin for the pure air of the deck, even in rainy or boisterous 
 weather, will be understood by all who have undertaken such 
 a voyage. The horrors of the crowded fore-cabin are happily 
 known to the writer only by description.* 
 
 down : this was stoutly refused by one of the five other passengers, 
 and an altercation arose, which was suddenly cut short by a young 
 midshipman thrusting his fist through the glass window, and, turning 
 to the supplicant for fresh air, to enquire whether he should break the 
 other also. This was declined ; the obstinate traveller sat in silence 
 during the rest of the journey; but the old gentleman, interested by 
 the bold and original conduct of his young friend, invited him to his 
 house, and afterwards became the means of greatly advancing his 
 prospects in life. 
 
 * I once took my passage in a steam-boat from Cologne to Rotterdam 
 (at that time a voyage of nearly forty hours), and found, when I had 
 got on board, that there was no sleeping accommodation. This was of 
 no consequence during the day time, and not of much consequence, 
 in fine weather, during the night to an old traveller ; but on this 
 occasion, as night advanced, a cold drizzling rain compelled the 
 passengers to seek refuge in the small cabin, the only one the vessel 
 afforded. When tea and supper were fairly over, and nightcaps of various 
 descriptions had been distributed among the guests, the low bench round 
 the cabin was completely occupied ; those who could sleep did so ; those 
 who could not, tried a variety of postures, looked wistfully at the four 
 comfortable corners occupied by envied sleepers ; some had slid down. 
 
 c 
 
26 DEFECTIVE VENTILATION 
 
 In our naval and merchant service much disease and mor- 
 tality are the direct consequences of defective ventilation. The 
 lower decks and close cabins of ships are often crowded with 
 people engaged in cooking, eating, drinking, and sleeping. 
 Their condition is bad enough in fair weather, but in a gale of 
 wind, with the scuttles closed and the hatches fastened down, 
 and no means provided for the admission of fresh air below 
 but what can find its way by an opening of a few feet square ; 
 when the vitiated effluvia from the healthy, the sick, and 
 
 upon the floor ; others found a hard pillow by leaning forward on the 
 table before them ; and those who still kept awake, had an opportunity, 
 by the faint gleams of a lamp, to study this odd and not over cheerful 
 grouping. One of my companions, not being able to sleep, went on 
 deck and resigned his place to me. I thus got a place for my head, and 
 with my great coat for a pillow, I managed to pass, in a kind of restless 
 sleep, the most dreary portion of the night. Early in the morning, an 
 hour before day-break, I went on deck ; a moist fog rested sluggishly on 
 the water, and rendered the shore barely visible. At this time an inci- 
 dent occured which animated every one. A poor Dutch family was on 
 board, consisting of a man, his wife, and four children, and it was 
 suddenly proclaimed that the eldest boy had fallen overboard during the 
 night, and was lost. A man overboard is a startling subject on every kind 
 of water, and in every description of craft, and we wereall busy with 
 inquiries as to when and where and by whom he was last seen; search 
 was made in every corner of the vessel, but all to no purpose ; the boy 
 was certainly drowned, and there was no help for it. The father seemed 
 to receive the condolence of the passengers with characteristic Dutch 
 phlegm ; he lit his pipe and received in silent resignation a long and 
 apparently angry discourse from his wife ; we were all very sorry for 
 him and for her, when, lo ! the black tarpaulin, which covered a large 
 collection of goods on deck, was seen to move, and from under one of 
 ite folds a large round sleepy face appeared, and crawling forth, with a 
 yawn and a stretch, the object of our solicitude stood before us : the 
 parents expressed their joy in rather an odd manner, the mother 
 scolded, the father quietly put down his pipe and began to cuff the 
 boy rudely, and, but for the interference of some of the passengers, he 
 would probably have received a sound thrashing for venturing, as it 
 appeared, without leave, to sleep in certainly what seemed to be the most 
 comfortable part of the vessel. 
 
IN SHIPS, AND ITS EFFECTS. 27 
 
 perhaps the dying, come steaming up the same aperture down 
 which the fresh air is struggling to find its scanty way to the 
 miserable inmates, how can we wonder at the mortality of 
 seamen, especially in tropical climates. In troop or transport 
 ships, the constitutions of the men are frequently enfeebled, 
 instead of being strengthened by the voyage. Moreover, the 
 evils arising from want of ventilation are aggravated by the 
 horrors of sea-sickness j the sense of smell becomes morbidly 
 sensitive ; the bilge water, or that stagnant corrupt water 
 which lodges in the bottoms of tight vessels, emits the 
 offensive odour of sulphuretted hydrogen and other gases; and 
 these, combined with the closeness of the cabins in sailing 
 vessels, few can endure with impunity ; all this is even made 
 worse in steam-boats by the odour of the hot rancid tallow 
 used for greasing the engines. 
 
 Mr. Robert Ritchie, in an excellent paper on the ventilation 
 of ships,* quotes a letter from a naval friend on the African 
 coast, who says : " On the lower deck of our little craft 
 were stowed away one hundred persons, ship stores, cook's 
 coppers, &c. Never did I before feel so much the importance 
 of a thorough ventilation. To sleep in such an atmosphere is 
 next to impossible, and when exhausted nature sinks into 
 repose, it awakes with that sickly and feverish sensation 
 which betokens the derangement of your physical system, and 
 that you have been inhaling a poison which is slowly but 
 surely preying on the vitals of your constitution. That disease 
 and death should be frequent is only what every rational and 
 scientific person would expect. Climate is blamed for every 
 disease that appears in foreign stations, but I have not the 
 slightest doubt that the want of a thorough method of ventila- 
 tion on ship-board has, in very many cases, laid the system open 
 to disease, which, in more favourable circumstances, could have 
 been easily removed. The man who could improve the present 
 wretched system would be justly entitled to the thanks of 
 every humane and benevolent individual." 
 
 * Jameson's Edinburgh Philosophical Journal, 
 c 3 
 
28 DIFFUSION OF HEAT 
 
 Such is the condition of a small crowded sloop of war. In 
 large men-of-war the evils are less, on account of the ventila- 
 tion of the lower decks by the gun-ports ; these, of course, do 
 not exist in merchant vessels ; and in the lower, or orlop deck 
 of all ships, there is great difficulty in establishing a constant 
 uniform current of fresh air. 
 
 In these introductory remarks, we do not insist upon the 
 necessity of warming our rooms and other enclosed spaces, for 
 that is an art which is practically well understood, and will re- 
 ceive a share of attention in this little work. But if warming is 
 easy and well understood, ventilation is also easy and badly 
 understood ; that is, it is very easy to ventilate a room or a 
 building, but the necessity for doing so is not generally 
 admitted by the great mass of the people, nor even by those 
 whose duty it is to teach them and to provide for the practice. 
 But to combine the two arts, to warm a room sufficiently, and 
 at the same time to ventilate it thoroughly, is not easy, for the 
 very means employed to ventilate a room, must necessarily 
 dissipate and carry away the heat employed in warming it. 
 Something, however, may and ought to be done to combine 
 the two methods, as we shall endeavour to shew ; but before 
 entering upon practical details, it is necessary to invite atten- 
 tion to such of the laws of heat as are more immediately 
 connected with our subject. We can scarcely do more, in 
 our limited space, than bring together a few of the results of 
 scientific principles, and refer the reader to larger and more 
 comprehensive treatises for their verification. 
 
 Heat is given off from bodies by two distinct processes 
 radiation and conduction. In radiation, rays of heat diverge 
 in straight lines from every part of a heated surface, and also 
 from extremely minute depths below such surface. These 
 rays, like rays of light, are subject to the laws of refraction 
 and reflection, and their intensity decreases as the square of 
 the distance. When we approach an open fire, or the surface 
 of a stove, we feel its heat by radiation, and it has been ascer- 
 tained that, at the ordinary temperature of hot water pipes, 
 
BY RADIATION. 29 
 
 about one-fourth of the total cooling effect is due to 
 radiation. 
 
 But the amount of radiation of a body heated above the 
 temperature of the surrounding atmosphere depends greatly 
 upon the nature of its surface. If a vessel of hot water, coated 
 with lamp black, radiate 100 parts of heat within a given 
 time, a similar vessel, containing water of the same tempera- 
 ture, coated with writing paper, will radiate 98 parts of heat ; 
 resin, 96 ; China ink, 88 ; red lead, or isinglass, 80; plumbago, 
 75 ; tarnished lead, 45 ; tin, scratched with sand paper, 22 ; 
 mercury, 20 ; clean lead, 19 ; polished iron, 15 ; tin plate, 12. 
 
 In order to ascertain the velocity of cooling for a surface of 
 cast iron, Mr. Hood selected a pipe 30 inches long, 2^ inches 
 diameter internally, and 3 inches diameter externally. The 
 rates of cooling were tried with different states of the surface ; 
 first, when covered with the usual brown surface of protoxide 
 of iron ; next it was varnished black, and finally the varnish 
 was scraped off, and the pipe painted white with two coats of 
 lead paint. The ratios of cooling 1 were found to be for the 
 black varnished surface 1.21 minutes ; for the iron surface, 
 1.25 minutes, and for the white painted surface, 1.28 minutes. 
 " These ratios are in the proportion of 100, 103.3, and 105.7 ; 
 but, as the relative heating effect is the inverse of the time of 
 cooling, we shall find that 100 feet of varnished pipe, 103^ 
 feet of plain iron pipe, or 105| feet of iron pipe, painted white, 
 will each produce an equal effect."* 
 
 Leslie found that tarnished surfaces, or such as are roughened 
 by emery, by the file, or by drawing streaks or lines with a 
 graving tool, had their radiating power considerably increased. 
 But, according to Melloni, the roughness of the surface merely 
 acts by altering the superficial density which varies according 
 as the body is of a greater or less density, previous to the 
 alteration of its surface by roughening. The following experi- 
 ment gives the data for this conclusion : Melloni took four 
 
 * Practical Treatise on Warming Buildings, &c., London, 1844. 
 
30 RADIATING SURFACES. 
 
 plates of silver, two* of which, when cast, were left in their 
 natural state, without hammering, and the other two were 
 planished to a high degree under the hammer. All four plates 
 were then finely polished with pumice-stone and charcoal, and 
 after this, one of each of the pairs of plates was roughened, by 
 rubbing with coarse emery paper in one direction. The 
 quantity of heat radiated from these plates was as follows : 
 
 Hammered and polished plate 10 
 
 Hammered and roughened plate 18 
 
 Cast and polished plate 13.7 
 
 Cast and roughened plate 11.3 
 
 Thus it appears that the hard hammered plate was increased 
 in radiating power four fifths, by roughening its surface, while 
 the soft cast plate lost nearly one fifth of its power by the same 
 process. 
 
 When a body is exposed to a source of heat, a portion of it 
 is absorbed, and it has been proved, experimentally, that the 
 absorptive power of bodies for heat is precisely equal to their 
 radiative power. It was long supposed that colour had great 
 influence on radiation and absorption. By exposing variously 
 coloured surfaces to the heat of the sun, their absorbing power 
 was in the following order black, blue, green, red, yellow, and 
 white. Hence it would naturally be expected, that the 
 radiating powers of differently coloured bodies would be in 
 this order, and that by painting a body of a dark colour we 
 should increase its radiating power. Such, however, is not the 
 case, for the absorption and radiation of simple heat, or lieat 
 without light, depend on the nature of the surface rather 
 than on colour. Heat of low temperature, or that which 
 proceeds from bodies of low temperature, becomes less con- 
 nected with colour the lower the temperature. 
 
 The numbers which represent the radiating powers of 
 different bodies for invisible or non-luminous heat, or heat of 
 low temperature (as given above), evidently bear no relation 
 to colour, for lamp-black and writing paper are nearly equal ; 
 
CONDUCTION AND CONVECTION. 31 
 
 Indian ink is much less, and plumbago still less. A ther- 
 mometer bulb, coated with a paste of chalk, is affected by 
 invisible heat even more than a similar one coated with 
 Indian ink ; but this result does not occur when the heat is 
 from a luminous source. Thus it was found by Scheele that 
 when two spirit thermometers, one containing coloured, and 
 the other colourless alcohol^ were exposed to the sun, the 
 coloured liquid rose much more rapidly than the colourless, 
 but when they were both plunged into a vessel containing 
 hot water, they rose equally in equal times. 
 
 The propagation of heat by conduction is a very different 
 process from that of radiation. By conduction, the heat 
 travels through or among the particles of solid matter and is 
 gradually communicated by one group of particles to the 
 neighbouring group, and by this to the next group, and so on, 
 until the temperature of the body in contact with the source 
 of heat is raised more or less above the temperature of the 
 air. When heat is communicated to a fluid body, the process 
 is different. In consequence of the great mobility of its 
 particles, those which first come under the action of the source 
 of heat, being raised in temperature, escape from its influence, 
 and ascend through the fluid mass, distributing a portion of 
 their acquired heat among other particles on its way ; other 
 particles immediately take its place, and being heated, ascend 
 in like manner, and distribute their heat. By this process 
 of convection, as it is called, the whole of the particles in a 
 confined mass of fluid come under the action of the heating 
 body ; those first heated, escape as far as possible from the 
 source of heat, and becoming cooled, descend again to be heated, 
 and again to ascend and descend. In this way a circulation 
 is maintained in the whole mass of fluid. 
 
 It is only by this process of convection that air may be said 
 to be a conducting body, for if a mass of air be confined in 
 such a way as to prevent the free motion of its particles, it 
 ceases almost entirely to conduct heat, and may be usefully 
 employed to retain heat ; as in the case of double windows, 
 
32 CONDUCTION OP HEAT. 
 
 the enclosed mass of air prevents the heat from escaping from 
 the apartment, and shields the glass which is in contact with 
 the warm air of the room from the cooling action of the 
 external air. According to some experiments by Mr. Hood, 
 each square foot of glass will cool 1.279 cubic feet of air 1 
 per minute, when the temperature of the glass is 1 above that 
 of the external air. This, however, is in a still atmosphere. The 
 cooling effect of external windows when exposed to the action 
 of winds has not been accurately determined. It appears that 
 the cooling effect of wind, at different velocities, on a thin 
 surface of glass, such as the bulb of a thermometer, is very 
 nearly as the square root of the velocity. But there are many 
 objections to applying the results obtained from the thin glass 
 of a thermometer bulb to the comparatively thick glass of 
 windows. Glass is a very bad conductor of heat, and the 
 cooling effect of wind upon it is not so great as is generally 
 supposed. 
 
 Solids differ greatly in their heat-conducting powers. If 
 gold conduct 100 parts of heat, platina will conduct 98.10 
 parts ; silver, 97.30 ; copper, 89.82 ; iron, 37.43 ; zinc, 36.30 ; 
 tin, 30.39; lead, 17.96; marble, 23.60; porcelain, 12.20; 
 fire-brick, 11.40. The slow conducting power of such 
 bodies as porcelain, brick and glass, may be contrasted with 
 the rapid conducting power of some of the metals by holding 
 one end of a piece of each substance in a flame ; the metal will 
 soon become too hot for the hand, while the porcelain may 
 be heated to redness in the flame without its being felt to 
 be much warmer at the other end. A practical application 
 of this property is also to be found in the materials of close 
 stoves for heating apartments ; for while those in which the 
 outer case consists of copper or iron receive their heat quickly 
 and part with it quickly, those which are lined with brick 
 and covered with porcelain receive their heat slowly, and 
 communicate it slowly to the air of the apartment. Much, 
 however, depends on the thickness of the metal casing, for, by 
 increasing this, it will, of course, retain its heat longer. 
 
RADIATING AND CONDUCTING POWERS. 33 
 
 When a heated body cools under ordinary circumstances," it 
 is by the united effects of radiation and conduction, and 
 the rate of cooling increases considerably, in proportion as the 
 temperature of the heated body is greater than that of the 
 surrounding medium. We have seen that the cooling effect of 
 radiation depends greatly on the nature of the surface ; but 
 it is a remarkable fact, that the cooling effect of the air by 
 conduction, has no reference to the nature of the surface ; it 
 is the same on all substances, and in all states of the surface of 
 those substances. The air, in contact with such surfaces, robs 
 them of a portion of heat, and immediately ascends to make 
 way for other portions of air, which repeat the process. By 
 these two processes the body cools down to the temperature of 
 the surrounding air, the conductive power of which varies 
 with its elasticity, or barometric pressure ; the greater the 
 pressure the greater also the cooling power. It has also been 
 shewn by Dulong and Petit, that the ratio of heat, lost by 
 contact of the air alone, is constant at all temperatures ; that 
 is, whatever is the ratio between 40 and 80 is also the ratio 
 between 80 and 160, or between 100 and 200. 
 
 It was long supposed that a certain relation existed between 
 the radiating and conducting powers of heated bodies, that 
 the variation between them was exactly proportional to the 
 simple ratio of the excess of heat; that is, supposing any 
 quantity of heat to be given off in a certain time, at a specified 
 difference of temperature, at double that difference twice the 
 quantity of heat would be given off in the same time. This 
 law does, to a certain extent, apply where low temperatures 
 are concerned, but does not hold at high temperatures. Thus, 
 in a set of experiments by Dulong and Petit, the total cooling 
 at 60 and 120 (Centigrade), was found to be about as 3 to 7; 
 at 60 and 180, as 3 to 13 ; and at 60 and 240, as 3 to 21 ; 
 whereas, according to the old theory, these numbers would 
 have been as 3 to 6, 3 to 9, and 3 to 12. When the excess of 
 temperature of the heated body above the surrounding air 
 is as high as 240 Cent., or 432 Fahr., the real velocity of 
 
 c5 
 
34 CAPACITY OF BODIES FOE HEAT. 
 
 cooling is nearly double what it would have been by the old 
 theory, varying, however, with the surface. 
 
 Since the heat lost by contact of the air is the same for all 
 bodies, while those which radiate most, or are the worst con- 
 ductors, give out more heat in the same time than those 
 bodies which radiate least, or are good conductors, it might be 
 supposed that those metals which are the worst conductors 
 would be best adapted for vessels or pipes for warming rooms 
 by radiation. " Such would be the case if the vessels were 
 infinitely thin ; but as this is not possible, the slow conducting 
 power of the metal (iron) opposes an insuperable obstacle to 
 the rapid cooling of any liquid contained within it, by prevent- 
 ing the exterior surface from reaching so high a temperature 
 as would that of a more perfectly conducting metal under 
 similar circumstances ; thus preventing the loss of heat both 
 by contact of the air and by radiation, the effect of both being 
 proportional to the excess of heat of the exterior surface of the 
 heated body. If a leaden vessel were infinitely thin, the liquid 
 contained in it would cool sooner than in a similar vessel of 
 copper, brass, or iron ; but the greater the thickness of the 
 metal, the more apparent becomes the deviation from this rule ; 
 and as the vessels for containing water must always have some 
 considerable thickness, those metals which are the worst 
 conductors will oppose the greatest resistance to the cooling of 
 the contained liquid." Hood. 
 
 The reflective power of different substances for heat is 
 inversely as their radiating power. If a surface of brass reflect 
 100 parts of heat ; a similar surface of silver will reflect 90 
 parts ; tin foil, 85 ; block tin, 80; steel, 70 ; lead, 60 ; tin foil, 
 softened by mercury, 10 ; glass, 10 ; glass, coated with wax, 5. 
 
 When similar substances are exposed to the same tempera- 
 ture, they all become heated to the same degree, as measured 
 by the thermometer, but if the temperatures of dissimilar 
 substances have to be raised to the same degree, the quantities 
 of heat required for the purpose will be very different for 
 different substances. Thus, if we place side by side, upon a 
 
SPECIFIC HEAT. 35 
 
 hot plate, two equal and similar vessels, one containing a 
 certain weight of water, and the other an equal weight of 
 mercury, the mercury will soon become much hotter than the 
 water. So also, on lowering the temperature of dissimilar 
 substances to an equal degree, some will give out more and 
 others less heat. Different bodies, therefore, display different 
 degrees of susceptibility for receiving free heat within their 
 molecules ; this is called their capacity for heat, and the 
 quantity required to raise equal masses or equal weights 1, 
 is termed their specific heat. The theory of specific heat is of 
 great importance in a practical point of view, for on it depend 
 many of the calculations for ascertaining the proportions 
 of the various kinds of apparatus employed in warming 
 buildings. 
 
 The specific heat of different substances can be ascertained 
 by mixing together, with certain precautions, ascertained 
 quantities of the substances under consideration, when their 
 mutual capacities for heat are determined by the decrease in 
 the temperature of the hotter body, and by its increase in the 
 cooler. Thus, if lib. of mercury at 32, and lib. of water at 
 62 be mixed together, the common temperature will be 61. 
 The temperature of the metal has, therefore, risen 30, while 
 that of the water has fallen 1. If the mercury had been at 
 62, and the water at 32, the common temperature of the 
 mixture would have been 33. In this case the water would 
 have gained 1 of temperature, and the mercury would have 
 lost 30. Thus it appears that the capacity of water for 
 heat exceeds that of mercury 30 times. If the water be taken 
 as unity, the specific heat of the mercury will be -$, 
 or 0.033. 
 
 Again, if lib. of iron filings at 68 be mixed with lib. of 
 water at 32, the temperature of the mixture will be 36. 
 That quantity of heat, therefore, the loss of which lowers the 
 temperature of iron 32, raises the temperature of water only 
 4 j so that eight times as much heat is required to raise cr 
 
36 CAPACITY OF BODIES FOR HEAT. 
 
 depress the temperature of the water 1, as would raise or 
 depress the temperature of an equal weight of iron 1. 
 Hence the specific heat of iron is ^, or 0.125. 
 
 The capacity of substances for heat may also be found 
 by observing the quantity of ice which the body under inves- 
 tigation is capable of thawing. Thus, if equal weights of iron 
 and lead be operated on, it will be found that the iron requires 
 a greater quantity of heat than the lead to produce the same 
 change of temperature, in the proportion of nearly 11 to 3. 
 If a bar of iron, in falling from 100 to 95, melt 11 grains 
 of ice, then a bar of lead of equal weight, under similar cir- 
 cumstances, would melt rather less than 3 grains ; heat is, 
 therefore, more effective in warming lead than iron. Again, 
 an ounce of mercury and an ounce of water, in falling from 
 60 to 55, will melt quantities of ice, in the proportion of 
 33 to 1000, or very nearly 1 to 30 ; that is, to raise water 
 from 55 to 60, requires a greater quantity of heat than to 
 raise an equal weight of mercury through the same range of 
 temperature, in the proportion of 30 to 1.* 
 
 * The quantity of ice melted by different kinds of fuel, affords a 
 convenient method of estimating their relative values. Thus it has 
 been found that 
 
 lib. of coal, of good quality, melts 901bs. of ice, 
 coke, 841bs. 
 
 wood, 321bs. 
 
 wood charcoal, 951bs. 
 
 peat, 191bs. 
 
 One method of estimating how much of the heat of a common fire is 
 radiated around it, and how much combines with the smoke, is to 
 allow all the radiant heat to melt a quantity of ice contained in a vessel 
 surrounding the fire, and all the heat of the smoke to melt the ice in 
 another vessel surrounding the chimney. By comparing the two quan- 
 tities of water thus obtained with the quantities of ice melted, it will 
 be found, according to Dr. Arnott, that the radiant portion of the heat 
 is, in ordinary cases, rather less than the combined, or less than half the 
 whole heat produced. 
 
SPECIFIC HEAT OF GASES. 37 
 
 The specific heat of bodies has been determined not only 
 for equal weights, but also for equal volumes, and this is called 
 their relative heat, which is to the specific heat of any sub- 
 stance directly as its specific gravity. It may be found by 
 multiplying the specific heat into the specific gravity; and 
 conversely, the specific heat may be found by dividing the 
 relative heat by the specific gravity. Now as the quantity of 
 heat required to raise the temperature of lib. of water 1 
 is sufficient to raise lib. of mercury 30, we say that the spe- 
 cific heat of mercury is T ^, taking water as unity ; and since 
 the specific gravity of mercury is about 13.6, it follows 
 that the relative heat of an equal volume of this metal is 
 ^ x 13.6 = 0.453. 
 
 With respect to gaseous bodies, it has been found that their 
 specific heat is inversely as their specific gravity or density; 
 and, consequently, equal weights of such gases contain a larger 
 quantity of heat, less their specific gravity. But as the 
 relative weights of equal volumes of gas are inversely as their 
 specific gravities, it follows that equal volumes of these gases 
 will have equal relative heat ; that is, they will contain equal 
 quantities of heat as the atmospheric air itself. This, how- 
 ever, refers to mixtures of gases, for when they are chemically 
 combined, they have a different relative heat, which exceeds 
 that of common air, and each such gas has a distinct index to 
 express its relative heat, so that the quantity of heat contained 
 in them exceeds that contained in an equal volume of atmos- 
 pheric air. The capacity of atmospheric air is taken as the 
 unit by which to estimate the specific heat of gaseous bodies ; 
 but sometimes that of water is assumed as the unit, and then 
 the capacities of gases are comparable with those of 
 solids and liquids. The latter values are obtained by mul- 
 tiplying the former into 0.2669, which is the index of, 
 the specific heat of atmospheric air compared with that of 
 water. 
 
 The following table shews the specific heat of various sub- 
 stances referred to water as the standard, and are supposed to 
 
38 SPECIFIC HEAT. 
 
 represent the quantity of heat contained in equal weights of 
 the several substances : 
 
 Water .... 1.0000 Carbonic acid . 0.2210 
 
 Aqueous vapour . 0.8470 Carbonic oxide . 0.2884 
 
 Alcohol . . . 0.7000 Charcoal . . . 0.2631 
 
 Ether .... 0.6600 Sulphur . . . 0.1850 
 
 Oil 0.5200 Wrought iron . 0.1100 
 
 Air 0.2669 Mercury . . . 0.0330 
 
 Hydrogen . . . 3.2936 Platinum . . . 0.0314 
 
 Nitrogen . . . 0.2754 Gold . , . . 0.0298 
 
 Oxygen . . . 0.2361 
 
 It appears, however, that bodies do not possess the same 
 capacity for heat at all temperatures, but that it increases with 
 the temperature ; the quantity of heat given out by any sub- 
 stance in cooling a given number of degrees, is greater at high 
 temperatures than at low ones. 
 
 The method of ascertaining the specific heat of gases is as 
 follows : The gas to be examined is well dried, and then 
 brought from a vessel, surrounded with water at 212, gra- 
 dually through a spiral tube, surrounded by cold water, the 
 gas escaping through the opposite end of the spiral. In the 
 course of its passage, the gas parts with a portion of its heat to 
 the cold water which surrounds the spiral, and the temperature 
 of the water gradually rises, until after some time it becomes sta- 
 tionary. The equilibrium thus established between the water 
 and the gas is measured by a thermometer, so as to find both 
 the rise in the temperature of the water, and the fall in that 
 of the gas. If the experiment be made with some other gas, 
 and the result should give a higher temperature to the water, 
 then this second gas must have imparted to the fluid a greater 
 amount of heat than the former one did ; if, on the contrary, 
 the temperature of water be less this time than before, it will 
 have given out less heat, and the respective capacities for heat 
 of these two gases will be proportional to the temperatures of 
 the water through which they have been admitted. The 
 
LATENT HEAT. 39 
 
 capacity of atmospheric air being taken as the unit, the specific 
 heat of other gases may be expressed by proportionate num- 
 bers. To raise lib. of water from 32 to 212, requires the 
 same quantity of heat as will raise 41bs. of atmospheric air 
 the same number of degrees. The specific heat of air is 
 therefore -J- or, more exactly, 0.2669 that of water, as stated in 
 the above table. 
 
 "When heat is added to a solid body, the first effect which 
 marks the increase of temperature is expansion; that is, the 
 cohesive or attractive force becomes more and more opposed by 
 the repulsive force of heat; the particles are consequently 
 separated to greater distances, and the temperature rises. At 
 a certain point, however, the temperature, as marked by the 
 thermometer, becomes stationary, and although the heat be 
 continually applied, the temperature does not rise. The solid 
 is now undergoing a change of state ; it is passing from the 
 solid into the liquid state; and no rise in temperature will be 
 observed until the whole of the solid has become liquid. The 
 point at which a body begins to fuse or melt, is called its 
 fusing point or point of liquefaction, and is different in 
 different substances. The quantity of heat absorbed by the 
 body, and unaccounted for, as far as the thermometer is con- 
 cerned, is called latent heat. When the body is liquefied, the 
 temperature again begins to rise, until another point is 
 attained, when it again becomes stationary, and the liquid 
 begins to pass off in the form of vapour or steam. This point 
 is called the boiling point, and is different in different sub- 
 stances. The heat absorbed during the process of boiling or 
 vaporization is also called latent. 
 
 If, for example, a quantity of snow, at the temperature of 
 zero, with a thermometer in it, be placed in a vessel on the fire, 
 the temperature will be observed to rise to 32; the snow 
 will then immediately begin to be converted into water, and 
 the thermometer will become stationary at 32, until the 
 whole of the snow is melted. This temperature is, therefore, 
 the melting or fusing point of snow or ice, and the heat ab- 
 
40 HEAT OF LIQUEFACTION. 
 
 sorbed or rendered latent during the process, being that which 
 is necessary to produce liquefaction, is hence called also the 
 heat of liquefaction, and amounts to no less than 140 ; that 
 is, although snow or ice may be of the same temperature as 
 water, yet the water actually contains 140 of heat more than 
 the solid snow or ice. As soon as the whole of the snow is 
 melted, the temperature of the water will begin to rise, and 
 will continue to do so until it reaches 212, when the boiling 
 point of water is -attained. While steam is rapidly escaping, 
 the water remains at 212 ; the heat which is absorbed, called 
 the heat of vaporization, being that which is required to main- 
 tain water in the state of vapour or steam, amounts to no 
 less than 1000 of temperature; that is, although water may 
 be at 212, and steam may be at 212, yet the steam contains 
 a larger amount of heat than water, such as is represented by 
 1000 on the scale of the thermometer. 
 
 In the following table the melting points of a few substances 
 are noted, together with the quantity of heat rendered latent 
 by each in passing from the solid into the liquid state. From 
 these, and ether results, it may be seen that, in general, the 
 higher the point of fusion, the greater will be the quantity of 
 heat absorbed in liquefaction. There is, however, no propor- 
 tion between these effects, for ice and spermaceti melt at 32 
 and 112, and yet the quantities of heat rendered latent are 
 nearly the same. 
 
 Melting Point. Latent Heat. 
 
 Water .... 32 ... 140 
 
 Sulphur. ... 213 ... 143.7 
 
 Spermaceti. . . 112 ... 145 
 
 Lead .... 612 ... 162 
 
 Bees' Wax . - . 150 ... 175 
 
 Zinc .... 773 ... 493 
 
 Tin .... 442 ... 500 
 
 Bismuth . . . 476 ... 550 
 
 In the following table the boiling points of a few substances 
 
LATENT HEAT OF STEAM. 41 
 
 are given, together with the quantity of heat rendered latent 
 by each in passing from the liquid into the aeriform state. 
 
 Boiling Point. Latent Heat. 
 
 Water 212 .... 1000 
 
 Alcohol (sp. gr. 0.7947) 173 (barom. 29.5) 457 
 
 Ether 98 .... 312.9 
 
 Oil of Turpentine . . 314 .... 183.8 
 Nitric Acid (sp.gr. 1.50) 210 .... 550 
 
 Ammonia 865.9 
 
 Vinegar 903 
 
 Petroleum 183.8 
 
 When water is boiling in an open vessel, the steam which 
 escapes from it is of the same pressure and elasticity as the 
 atmospheric air, and at 212 is equivalent to 30 inches of 
 mercury. In a close vessel, however, the temperature of the 
 steam may be increased to any extent, and is only limited by 
 the strength of the vessel containing it. Thus, at 212, the 
 pressure of the steam is equal to one atmosphere, or 151bs. on 
 every square inch of surface ; at 250, the pressure of the 
 steam, tending to burst the vessel containing it, is equal to two 
 atmospheres, or 301bs. on the square inch ; at 275, the 
 bursting pressure is that of three atmospheres, or 451bs. on 
 the square inch, and so on. But it is a remarkable fact, that 
 at all temperatures and pressures, the steam contains exactly 
 the same absolute quantity of heat ; for while the temperature, 
 as measured by the thermometer, increases almost indefinitely, 
 the latent heat of high-pressure steam diminishes in exactly 
 the same ratio, so that the sum of the latent and sensible heat 
 of steam always amounts to 1800 above the freezing point of 
 water. Thus a certain weight of steam at 212, when 
 condensed into water at 32, gives out 180 of sensible 
 heat, and 1000 of latent heat =1180 ; and the same weight 
 of steam at 400, condensed into water at 32, gives out 368 of 
 sensible heat, and 812 of latent heat=1180. The same 
 fact may be observed with steam at all other temperatures. 
 
42 HOT WATER AND STEAM PIPES. 
 
 These details respecting latent heat will enable the reader to 
 compare the merits of the two systems of heating buildings by- 
 pipes filled with hot water, and by similar pipes filled with 
 steam. 
 
 In the former system, it is not desirable to raise the water 
 to the boiling point (212), because, in such ca^se, steam would 
 be formed, and this escaping by the safety pipe, would abstract 
 much useful heat from the apparatus. In the latter system, 
 it is desirable to maintain the pipes at 212, because, at a lower 
 temperature, the steam would condense, and also absorb much 
 useful heat from the apparatus. From the necessity of main- 
 taining the temperature of 212 in steam pipes, it is evident 
 that a given length of steam pipe will afford more heat than 
 the same quantity of hot water pipe ; but the following re- 
 marks by Mr. Hood, on the relative permanence of tempera- 
 ture of the two methods, will shew an advantage in favour of 
 the hot water system : 
 
 "The weight of steam, at the temperature of 212, com- 
 pared with the weight of water at 212, is about as 1 to 1694; 
 so that a pipe which is filled with water at 212 contains 1694 
 times as much matter as one of equal size filled with steam. 
 If the source of heat be withdrawn from the steam pipes, the 
 temperature will soon fall below 212, and the steam imme- 
 diately in contact with the pipes will condense ; but in con- 
 densing, the steam parts with its latent heat ; and this heat, 
 in passing from the latent to the sensible state, will again 
 raise the temperature of the pipes. But as soon as they are 
 a second time cooled down below 212, a further portion of 
 steam will condense, and a further quantity of latent heat 
 will pass into the state of heat of temperature; and so on, 
 until the whole quantity of latent heat has been abstracted, 
 and the whole of the steam condensed, in which state it will 
 possess just as much heating power as a similar bulk of water 
 at the like temperature ; that is, the same as a quantity of water 
 occupying -j^Vr part of the space which the steam originally 
 did, 
 
EVAPORATION. 43 
 
 " The specific heat of uncondensed steam, compared with 
 water, is for equal weights as .8470 to 1 ; but the latent heat 
 of steam being estimated at 1000, we shall find that the 
 relative heat obtainable from equal weights of condensed 
 steam and of water, reducing both from the temperature of 
 212 to 60, to be as 7.425 to 1 ; but for equal bulks, it will 
 be as 1 to 228, that is, bulk for bulk, water will give out 
 228 times as much heat as steam, on reducing both from the 
 temperature of 212 to 60. A given bulk of steam will, 
 therefore, lose as much of its heat in one minute, as the same 
 bulk of water will lose in three hours and three quarters." 
 
 But when the water and the steam are both contained in 
 iron pipes of the same dimensions, the rate of cooling will 
 differ from this ratio, in consequence of the greater quantity 
 of heat .contained in the metal than in the steam. The spe- 
 cific heat of iron being nearly the same as that of water, the 
 pipe filled with water will contain 4.68 times as much heat as 
 that which is filled with steam j and if the latter cools down 
 to 60 in one hour, the other will require about four hours and 
 a half to do the same. There are other circumstances to be 
 noticed hereafter, which cause the hot water apparatus to be 
 six or eight times (instead of 4-J-) more efficient as a source of 
 warmth than steam. 
 
 The process of boiling is by no means indispensable to the 
 formation and escape of steam or vapour ; for at all tem- 
 peratures below the boiling point, vapour is formed at the sur- 
 face of liquids, and escapes therefrom by a process called 
 spontaneous evaporation. The difference between this process 
 and ebullition is chiefly this : when a liquid boils, the vapour 
 which escapes therefrom constantly maintains the same tem- 
 perature, provided the pressure remain the same ; but evapo- 
 tion may go on at all temperatures and pressures, the quantity 
 of liquid evaporated depending on the temperature and the 
 amount of surface exposed ; or the pressure may be increased 
 or diminished, or removed altogether, without affecting the 
 result, or that quantity of vapour which can exist in a given 
 space at a given temperature j the saturation of that space 
 
44 SPONTANEOUS EVAPORATION. 
 
 requiring a longer time in proportion to the density of the 
 air contained in it, while in a vacuum the saturation is instan- 
 taneous ; this is the only difference. 
 
 We have seen that the pressure or elasticity of vapour at 
 212 is sufficient to support a column of mercury 30 inches 
 high ; the force of vapour at lower temperatures is also 
 measured by the length of the mercurial column which it will 
 support. Vapour at 200 will support 23.64 inches of mer- 
 cury; at 150, 7.42 inches; at 100, 1.86 inches; at 80, 
 1 inch; at 60, .524 inch; at 50, .375 inch; at 32, .2 inch. 
 
 The amount of evaporation, however, is greatly influenced 
 by the motion of the air which carries off the vapour from the 
 surface of a liquid as fast as it is formed. A strong wind 
 will cause twice as much vapour to be discharged as a still at- 
 mosphere. Dalton ascertained the number of grains weight 
 of water evaporated per minute from a vessel, 6 inches in 
 diameter, for all temperatures between 20 and 212, when 
 the air was still, or in gentle or brisk motion. When the 
 water was at 212, the quantity evaporated was 120 grains per 
 minute in a still atmosphere ; 154 grains per minute with a 
 gentle motion of the air, and 189 grains per minute with a 
 brisk motion of the air. The following is an extract from his 
 table between the temperatures of 40 and 60 : 
 
 Temp. Force of vapour in Evaporating force in grains 
 
 Fahr. inches of mercury. of water. 
 
 J Still. Gentle, Brisk. 
 
 40 . 0.263 . 1.05 . 1.35 . 1.65 
 
 42 . .283 . 1.13 . 1.45 . 1.78 
 
 44 . .305 . 1.22 . 1.57 . 1.92 
 
 46 . .327 . 1.31 . 1.68 . 2.06 
 
 48 . .351 . 1.40 . 1.80 . 2.20 
 
 50 . .375 . 1.50 . 1.92 . 2.36 
 
 52 . .401 . 1.60 . 2.06 . 2.51 
 
 54 . .429 . 1.71 . 2.20 . 2.69 
 
 56 . .458 . 1.83 . 2.35 . 2.88 
 
 58 . .490 . 1.96 . 2.52 . 3.08 
 
 60 .524 2.10 2.70 3.30 
 
FORMATION OF DEW. 45 
 
 The amount of spontaneous evaporation is also greatly 
 influenced by the quantity of vapour already existing in the 
 air. In order to find this, we must ascertain the dew point of 
 the air, or the temperature at which the vapour in the air 
 begins to condense, and then, by referring to the table, the 
 quantity of vapour in the air at the time can be found, and 
 this, deducted from the quantity shewn by the table to be 
 given off at the ascertained temperature of the evaporating 
 liquid, will give the quantity of water that will be evaporated 
 per minute. In finding the dew point, we must bring some 
 colder body into the air, or have the means of cooling some 
 body to such a point as shall just condense the vapour of the 
 air upon its surface. Dr. Dalton used a very thin glass vessel, 
 into which he poured cold water from a well, or cooled down 
 the water by adding a small portion of a freezing mixture. 
 If the vapour was instantly condensed, he poured out the 
 cold water and used some a little warmer, and so on, until 
 he could just perceive a slight dew upon the surface. The 
 temperature at which this took place was the dew point. In 
 Daniell's hygrometer, the cold is produced by the evaporation 
 of ether. Now suppose the dew point of the air to be 40, and 
 the temperature of the air and of the evaporating liquid to 
 be 60, with a still atmosphere, the vapour in the air, as 
 shewn by the table at 40, is 1.05 grains, which subtracted 
 from that at 60, or 2.10, gives 1.5 grains per minute as the 
 quantity of vapour given off from a surface six inches in 
 diameter. 
 
 During the spontaneous evaporation of wet surfaces, a 
 considerable degree of cold is produced by the quantity of 
 heat rendered latent by the formation of the vapour, and the 
 heat is mostly derived from the liquid itself, or the surface 
 containing it. By proper contrivances, water may be frozen, 
 in consequence of the abstraction of heat during the rapid 
 formation of vapour. When a person takes cold from wearing 
 wet clothes, the vapour from the wet clothes obtains its heat 
 from his body, and the chilling sensation is often the greater 
 
46 MOISTURE OF CLOSE ROOMS. 
 
 the warmer the air. A person with damp clothes, entering a 
 room filled with hot dry air, is very likely to take cold, on 
 account of the powerful effect of warm air in abstracting 
 moisture. 
 
 In a badly ventilated room, the moisture from the breath of 
 the inmates, and from the combustion of lamps and candles, 
 accumulates nearly to the point of saturation. This is well 
 shewn by an experiment of the late Professor DanielL The 
 temperature of a room being 45, the dew point was 39; 
 a fire was then lighted in it, the door and window shut, and 
 no air was allowed to enter ; the thermometer rose to 55, but 
 the point of condensation remained the same. A party of 
 eight persons afterwards occupied the room for several hours, 
 and the fire was kept up ; the temperature rose to 58, and 
 the point of condensation rose to 52. Now, if this room had 
 been properly ventilated, the vapour would have been removed 
 as it was formed, and with it the effluvia and impure air. 
 
PAET I. 
 
 CHAPTEE I. 
 
 ON THE METHODS OF WARMING HOUSES BY MEANS OF OPEN 
 FIRE PLACES, ETC., BEFORE AND AFTER THE INTRODUCTION OP 
 CHIMNEYS. 
 
 SOME useful and instructive results are obtained from the in- 
 quiry, how far the physical structure and mental character of 
 classes of persons are influenced by the comparative scarcity 
 and abundance of some of the prime necessaries of life. Ac- 
 cording to some writers, the unequal distribution of solar heat 
 over the earth, is the cause of marked differences in national 
 character j others refer the distinctive effects to the quality 
 of the air they breathe. According to Arbuthnot, air not 
 only fashions the body and the mind, but has also had 
 great influence in forming language. He imagines that the 
 close serrated method of speaking among northern nations, 
 was owing to their reluctance to open their mouths widely in 
 cold air, whence their speech abounds in consonants. So, on 
 the contrary, the natives of hot climates opening their mouths 
 wider, formed a softer language, and one abounding in vowels. 
 The Greeks, inhaling air of a fine temperate region, spoke 
 with open mouth, and toned their voice to sweet sonorous 
 accents. 
 
 But if such views as these be regarded as fanciful, there is, 
 however, much truth in the proposition, that the ease or 
 difficulty with which fuel is procurable, has a great effect in 
 promoting or interfering with the health and personal com- 
 
48 EFFECTS OF THE ABUNDANCE 
 
 forts of nations j and that these, by a reflex action, contribute 
 much to the formation of character. It has been remarked, 
 that formerly the county of Buckingham being overgrown 
 with wood, it was thought necessary to clear it away, on 
 account of the refuge it afforded to the numerous robbers who 
 infested the district. The people being thus deprived of 
 fuel, became in the course of time stunted in growth and 
 dulled in intelligence ; until, by the extension of inland navi- 
 gation, fuel became cheap, and then the inhabitants began to 
 improve. In the county of Lancaster, on the contrary, the 
 great abundance and cheapness of fuel are extremely favour- 
 able to health and comfort, and hence, according to Sir Gilbert 
 Blane, the Lancasterians, especially the females, have become 
 noted for their well-formed persons and handsome faces. In 
 Yorkshire, and other parts of England where fuel is abundant, 
 the people are generally well-grown, healthy, and intelligent, 
 and their average height is said to exceed that of the in- 
 habitants of other parts of England where fuel is scarce. The 
 Norwegians are generally well lodged, each house being 
 furnished with glass windows, and an iron kakle or stove, and 
 on this account they are a better grown race than the North- 
 Western Highlanders of Scotland, who procure their fuel 
 with difficulty, and consume it in a rude and unthrifty manner. 
 In France, where fuel is very scarce, the average height of a 
 man does not exceed 5 feet 4 inches ; in the Netherlands 
 where fuel is more abundant, the average height is 5 feet 6-t 
 inches ; and in England, where fuel is cheap and abundant, 
 the average height is upwards of 5 feet 9 inches ; in Sweden, 
 where wood is as abundant as our coal, the peasants are tall, 
 vigorous men, notwithstanding their uncleanly habits and 
 the rigour of the climate. 
 
 The comparative scarcity or abundance of fuel will, of 
 course, greatly determine the method of creating an artificial 
 climate within doors. In some parts of China, where fuel is 
 scarce, the people secure themselves from the cold of winter 
 by warm clothing, and this is probably a safer method even 
 
OR DEFICIENCY OF FUE 49 
 
 than our own, because with them the defence is constant and 
 uniform, while our in-door clothing is thin, and we rely for 
 warmth upon an atmosphere heated to the temperature of 
 summer. If the person be well clothed, the coldest atmos- 
 phere can be breathed with safety, and its effect is often 
 highly exhilarating, as in skating on the ice or in walking 
 briskly. We often enjoy the warmth of a bed while breathing 
 an atmosphere cold enough to freeze the water in the ewer. 
 Hence it is better, as Dr. Arnott remarks, to clothe so as 
 to feel comfortably warm in a room heated to 60, or 62, as a 
 steady temperature, which it would not be dangerous to enter 
 or to leave, than to dress lightly in a room heated by a common 
 fire to 70, or more, and which is liable to sink to 50, or less. 
 
 In Normandy, where the cold of winter is severe, and fuel 
 expensive, the lace-makers, in order to keep themselves warm, 
 and at the same time to save fuel, agree with some farmer, 
 who has cows in winter quarters, to rent the close sheds. The 
 cows are tethered in a row on one side of the shed, and the 
 lace-makers sit cross-legged on the ground on the other side, 
 with their feet buried in straw. The cattle, being out in the 
 fields by day, the poor women work all night for the sake of 
 the steaming warmth arising from the animals. 
 
 The Laplander, during eight months of the year, inhabits a 
 little hut with a small hole in the centre of the roof for the 
 admission of light and the escape of smoke, and obtains heat 
 from a smoky lamp of putrid oil, as the Esquimaux does in 
 his hut of snow. The effect of this arrangement is, that the 
 whole nation of Laplanders are afflicted with blear eyes. The 
 Greenlander, indeed, builds a larger hut, and contrives it 
 better, but it is often occupied by half a dozen families, each 
 having a lamp for warmth and for cooking, and the effect of 
 this arrangement, says Egede, " is to create such a smell, that 
 it strikes one not accustomed to it to the very heart." We 
 fear that a similar effect would be produced on any one of our 
 readers, were he to enter the huts of some of the Irish and 
 Scottish peasantry. 
 
 D 
 
50 BURNING OF FUEL 
 
 The method of obtaining warmth in Persia, is scarcely an 
 improvement on the smoky lamp of the Laplanders and Green- 
 landers. A large jar, called a kourcy, is sunk in the earthern 
 floor, generally in the middle of the room. This is filled with 
 wood, dung, or other combustible ; and when it is sufficiently 
 charred, the mouth of the vessel is shut in with a square 
 wooden frame, shaped like a low table, and the whole is then 
 covered with a thick wadded quilt, under which the family, 
 ranged around, place their knees to allow the hot vapour to 
 insinuate itself into the folds of their clothing ; or when they 
 desire more warmth, they recline with the quilt drawn up to 
 their chins. The immoveable position necessary for receiving 
 the full benefit of the glowing embers is inconvenient; and 
 the effluvia from the fuel is nauseous and deleterious. Head- 
 ache is always produced, and, from the number who sleep 
 entirely under the quilt at night, suffocation is not an un- 
 common accident. The kourcy also serves for an oven, and 
 the pot is boiled on its embers. This rude and unwholesome 
 method is adopted in the noblest mansions of the cities, as 
 well as in the dwellings of the poorer classes ; only, in the 
 former, a more agreeable fuel is burnt, and the ladies sit from 
 morning till night under rich draperies spread over the wooden 
 cover, endeavouring to overcome the soperific influence of the 
 foul air by occasional cups of coffee, or the delightful fumes of 
 the kalioum. 
 
 The burning of fuel in the midst of an apartment, is by no 
 means confined to nations whom we are in the habit of calling 
 barbarous and uncivilised. In Seville and other parts of Spain, 
 preparations for winter are made about the middle of October. 
 The lower summer apartments are stripped of their furniture, 
 and the chairs and tables are removed to other rooms on the 
 opposite side of the court. The brick floors are covered with 
 thicker mats than those used in the warm season. A flat and 
 open brass pan, about two feet in diameter, raised a few inches 
 from the ground by a round wooden frame, on which those 
 who sit near it may rest their feet, is used to burn a sort of 
 
IN OPEN APARTMENTS. 51 
 
 charcoal, made of brushwood, called cisco. The carbonic acid 
 vapour is most injurious to health ; but such is the effect of 
 habit, that the natives are seldom aware of the inconveniences 
 arising from the stifling fumes of their braziers. 
 
 The charcoal brazier is a very ancient method of warming 
 an apartment ; the Greeks and other nations commonly used 
 it, and sought to correct the deleterious nature of the fumes, 
 by burning costly odorous gums, spices, and woods. 
 
 The braziers of the Romans were elegant bronze tripods, 
 supported by satyrs and sphinxes, with a round dish above for 
 the fire, and a small vase below to hold perfumes. A kind of 
 close stove was also used ; but, in either case, the smoke was so 
 considerable, that the winter rooms were differently furnished 
 from those appropriated to summer use. The former had 
 plain cornices and no carved work or mouldings, so that the 
 soot might be easily cleared away. In order to prevent the 
 wood from smoking, the bark was peeled off, and the wood 
 kept long in water, and then dried and anointed with oil. It 
 is not, however, evident how this plan should prevent the 
 smoke of the burning fuel. 
 
 The great convenience of the brazier, and the apparent 
 cleanliness of the fuel, are arguments in favour of its continued 
 use even in our own day. A visitor to some of our beautiful 
 cathedrals in winter, during the time of divine service, Salis- 
 bury Cathedral for example, will be astonished to see on the 
 floor of the choir two or three enormous braziers full of live 
 charcoal ; a peculiar odour arises from them, and pervades the 
 building; a pleasing sensation creeps over the whole frame, 
 and the tendency to sleep is often irresistible; persons troubled 
 with cough cease to cough, and an unusual effort is required 
 when the service is over to rise and quit the building. The 
 enormous size of the enclosure prevents any fatal effects from 
 the abundant evolution of carbonic acid, nor have we ever 
 heard of any well-authenticated case of injury to any one ; but 
 a very little consideration will shew that, in a smaller space, 
 such as a room, this primitive method of obtaining warmth 
 
 D2 
 
52 EFFECTS OF BURNING CHARCOAL. 
 
 might lead to dangerous consequences. A single pound weight 
 of charcoal consumes in burning 2 T 6 -lbs. weight of oxygen, 
 which is the quantity contained in between 13 and 141bs. 
 weight of atmospheric air. Now, a good-sized room, 20 feet 
 by 13 feet, and 10 feet high, does not contain more than about 
 200 pounds weight of air, and as the combustion of one pound 
 of charcoal produces 3-^lbs. of carbonic acid, which, by min- 
 gling with the rest of the air of the apartment, renders, at 
 least, 3 Gibs, weight of air unfit for respiration, making in all 
 about 501bs. weight of air, it follows that, in such a room, the 
 air will require, for healthy respiration, to be renewed many 
 times an hour. 
 
 The fatal effects of the charcoal brazier, in a close room, are 
 too frequently illustrated in the deaths of suicides, as recorded 
 in our newspapers. At the time we are writing, a picture 
 dealer, near Hanover Square, has just availed himself of this 
 fatal instrument. But, perhaps, the most remarkable case of 
 self-destruction in this way, is that of the promising son of 
 Berthollet, the celebrated chemist, for the fatal act was con- 
 ducted with all the method and precision of a scientific 
 experiment. This young man became affected with great 
 mental depression, which rendered his life insupportable to 
 him. Retiring to a small room, he locked the door, closed 
 up every chink and crevice which might admit fresh air, 
 carried writing materials to a table, on which he placed a 
 seconds' watch, and then seated himself before it. He now 
 marked the precise hour, and lighted a brazier of charcoal before 
 him. He continued to note down the series of sensations he 
 then experienced in succession, detailing the approach and 
 rapid progress of delirium, until, as time went on, the writing 
 became larger and larger, more and more confused, and at 
 length illegible, and the young victim fell dead upon the floor. 
 
 In many trades, the workmen are habitually exposed to the 
 fumes of burning charcoal : bookbinders, engravers, cooks, &c., 
 suffer much in health from this cause ; and it is rare to find that 
 any means are taken to ventilate the places in which they work. 
 
THE HYPOCAUST OF THE ROMANS. 
 
 53 
 
 In addition to the brazier, the ancient Romans were ac- 
 quainted with flues for warming rooms and buildings; but 
 as these were costly contrivances, their use was confined to the 
 wealthy. These flues, forming what was called the hypo- 
 caustum, were conducted below the floor of the room intended 
 to be warmed. The hypocausts were of two kinds the 
 first, constructed with flues running under the floor, and 
 heated from a fire-place on the outside of the building ; and 
 the second kind formed like a low chamber, having its ceiling 
 supported by small pillars or by dwarf walls, and sometimes 
 with flues leading from them to other apartments. The hypo- 
 caust discovered at Lincoln, of which figures 2 and 3 are a 
 ground plan and a section, will explain this construction. 
 
 This hypocaust was 24J feet long and 9^ feet wide ; it con- 
 tained four rows of brick pillars, a a, cc, two of which were 
 square and two circular. The square pillars, a a, were 8 inches 
 on the side and about 9 inches apart ; the circular ones, c c, 
 were 1 1 inches in diameter. Each pillar rested on a brick or 
 tile for its base, and another tile formed its capital ; thus making 
 its height, which was that of the heating chamber, about 26 
 inches. The ceiling of the hypocaust was formed of large 
 bricks j on them were placed courses of tiles, bedded in 
 mortar, and on them a layer of stucco, to form the floor of the 
 
54: HYPOCATJSTS USED 
 
 room 2 to be heated j the entire thickness of the floor being 
 
 about 10 inches. The fire-hearth was at i; and the flame and 
 
 smoke passed through the arched cavity or throat of the 
 
 furnace / into the hypocaust. Two flues, m n, opened into the 
 
 hypocaust ; the flue m, which probably conducted the smoke 
 
 and hot air under some other apartment, was about 6 inches 
 
 high and 14 inches inside ; its bottom was raised about 2 
 
 inches above the floor of the hypocaust. The flue n was about 
 
 G inches square, and placed as much under as above the floor 
 
 of the hypocaust j this seems to have been a smoke flue. The 
 
 position given to these flues was probably intended to retain 
 
 at all times the hottest portion of the vapour in contact with 
 
 the ceiling of the hypocaust. The floor of the prsefurnium 
 
 was 18 inches under the level of the floor of the hypocaust. 
 
 The large space provided for the combustion of the fuel and 
 
 the entrance of air, was necessary for conveying a heated 
 
 current through the flues, as the Romans were unacquainted 
 
 with the method of procuring a draught by the use of a 
 
 chimney. Some approach, however, appears to have been 
 
 made towards the invention of a chimney, for Vitruvius, in 
 
 describing the construction of the hypocaust for heating the 
 
 caldarium or sweating room of a bath, directs that the 
 
 floor be made inclining, so that a ball placed on any part of it 
 
 would roll towards the fire-place, by which means the heat 
 
 would be more equally diffused in the sweating chamber. 
 
 The hypocaustrum is well known to the Chinese, and is in 
 common use about Pekin, where the winter climate is very 
 severe. The houses of the better class are built with double 
 walls and with hollow flues extending beneath the floors. The 
 fire-place is constructed either against the exterior wall of the 
 apartment to be heated, or in an inferior room adjoining ; by 
 which means the annoyance from dust and smoke are avoided, 
 as well as the inconvenience of servants entering the room to 
 attend to the fire. From the fire chamber proceeds a main 
 flue, which is connected with the horizontal flue, a b, (Fig. 4). 
 From this another flue, c d, proceeds at right angles to about 
 three fourths of the extent of the room ; these flues are per- 
 
- 4- 
 
 BY THE CHINESE. 55 
 
 forated with holes at proper distances, in order to give out 
 
 the smoke and heated air equally 
 over the whole area of the floor- 
 ing. Two horizontal flues are 
 built in or attached to the side 
 walls, as at/#, in order to carry 
 off the smoke into the external 
 air. The flooring of the apartment 
 consists of flat tiles or flagstones, 
 neatly embedded in cement, so as to prevent the escape of the 
 smoke or heated air from the flues beneath into the room ; 
 these stones or paving tiles, resting on blocks of stone or bricks, 
 may be of any thickness required for the extent of the air 
 flues which are employed. By this contrivance, the heat, 
 coining in contact with every part of the floor, is uniformly 
 diffused over the apartment. The floors, also, being very im- 
 perfect conductors of heat, being once sufficiently heated by 
 the flues, and the apertures of the main flues outside being 
 stopped, retain a sufficient heat for domestic comfort during 
 many hours. The paving tiles of the rooms are often made of 
 ornamental porcelain ware of considerable thickness. Even 
 the benches and sleeping places are warmed by this contrivance. 
 These are built hollow, with bricks, in the form of a square 
 bench or oblong bed, and communicating with the flues, or 
 having their own separate flue, are thus heated. Those who 
 dislike lying on the hot bricks, or on the felt mat that is 
 spread over them, suspend from the ceiling over the heated 
 bench a kind of hammock, made of coarse cloth ; and thus they 
 enjoy warmth and repose. In the morning, the bed places 
 are covered with carpets and mats, on which the inmates sit. 
 
 The ingenious economy of the Chinese (from which we might 
 often borrow a useful lesson), prevents the flues from becoming 
 choked by soot. Instead of employing pit coal of good 
 quality, they make use of the inferior or small refuse coal for 
 this purpose,* and mix it with a compost of clay, earth, cow- 
 
 * It is worthy of reproachful remark, that during many years the 
 
56 CHINESE KANGS. 
 
 dung, or any refuse vegetable matter ; and then form it into 
 balls, which are dried in the sun or open air. This method 
 is not adopted on account of any scarcity of fuel, for coal is 
 abundant in China ; but the Chinese, unlike the English, know 
 how to take care of it. They find that their fire-balls, during 
 combustion, give out very little smoke j and they are largely 
 manufactured in the coal districts, and distributed by canal 
 carriage over a large portion of the empire. 
 
 In the inferior class of houses, instead of having the fire out- 
 side the house or room to be heated, it is built in the corner of 
 the dwelling room. A pit is dug for the body of the fire 
 chamber and draught-hole ; and the top, or head of the stove, 
 is used for the different operations of cooking. 
 
 That no portion of heat may be lost, or escape into the room 
 directly from the fire, beyond what is necessary to maintain a 
 given temperature, vessels of water are placed on the head of 
 the stove, and thus the heat, which would otherwise be lost, 
 is absorbed and economised ; while it affords, by its evaporation, 
 the necessary supply of moisture to preserve the atmosphere of 
 the room in a healthy condition as to moisture. 
 
 The Chinese call a stove which is heated by a furnace, a 
 kang ; the ti-kang is a furnace of which the flue runs under the 
 floor or pavement of a room ; and the kao-lcang is that used for 
 heating benches and beds. There is yet a third variety, the 
 tong-kang, which is formed in the wall, and this differs from the 
 ti-kang only in being perpendicular instead of horizontal. In 
 the tong-kang, the heating flue is carried along the floor, with 
 openings from it, at which the heated air and smoke ascends 
 into the spaces of a hollow wall. A tong-kang was erected by 
 Sir William Chambers, in 1761, for heating the orangery at 
 Kew Palace. In imitation of the Chinese method, he intro- 
 duced heated air through an air pipe or flue in contact with 
 
 coal owners of the north of England burnt to waste their small refuse 
 eoal at the mouth of the pit. A million tons a year have thus been 
 wantonly destroyed ; it is now, however, used for manufacturing coke 
 for the use of our locomotive engines. 
 
THE HOUSES OF "OLD ENGLAND." 57 
 
 Flg - 5 ' the heating flues. In Fig 5, the flue from the 
 furnace is shewn at a, the tong-kang flues at c, and 
 the hot-air flue at e. 
 
 It is scarcely possible to improve upon these re- 
 finements of the Chinese, except by the introduction 
 nof the chimney, the origin of which has been the 
 subject of much learned discussion. The tong-kang, 
 or perpendicular flue, is in effect a chimney, and 
 doubtless acts as such. Before the introduction of this 
 important addition to domestic comfort, about the 
 fourteenth century, the houses, even of the wealthy, 
 must have been wretched abodes, at least according to modern 
 ideas of comfort. "The spacious lofty hall, left open to the roof, 
 had its windows placed high from the floor, and filled with oiled 
 linen or louver boards, or occasionally with painted glass. Its 
 clumsy unframed doors were opened by latches; and when the 
 walls were not coarsely painted in the fashion of the time, 
 they were left rough, and covered with arras, suspended by 
 hooks, at a distance of three or four inches from the wall. 
 The floor, of stone or earth, had a part at one end raised a 
 little above the general level, and laid with planks. On this 
 platform or dais stood a massive table and ponderous benches 
 or forms, and a high-backed seat for the master, under a 
 canopy. On the hearth, in the middle of the hall, were placed 
 the andirons for supporting the ends of the brands, that 
 were arranged by means of a heavy two-pronged fork, the type 
 and predecessor of the mode'rn poker. On the roof, over the 
 hearth, was a turret or louver, filled with boards, so arranged 
 as to exclude rain and wind, and permit the escape of smoke ; 
 and this was sometimes an object of considerable architectural 
 beauty in the external aspect of the building." In modern halls, 
 the louver is still retained as an architectural feature, although 
 the uses for its erection have happily long ceased to exist. 
 
 " In this gaunt and aguish apartment, heated by a single 
 fire, the company were in a position not much different from 
 what they would be in the open air ; not a particle of heated 
 air could add to their comfort, for, as fast as produced, it 
 
 D5 
 
58 OLD ENGLISH CASTLES. 
 
 escaped through the louver : light was the only solace the 
 greater number could derive from the blazing fuel; and the 
 few who were in a situation to feel the radiant heat, were in- 
 commoded by the current of cold air sweeping like a hurri- 
 cane along the floor towards the fire. From the height of 
 the louver, and low temperature of the smoke, few of the 
 buoyant flakes of charcoal found their way into the atmos- 
 phere, and the larger the bonfire, the thicker was the layer of 
 soot deposited on each individual. Boisterous weather also 
 brought its annoyance. Had the fire been made in an open field, 
 they might have moved to the windward of the smoke; but 
 in the hall, where could they flee from its miseries?"* 
 
 The houses of small landholders and farmers were generally 
 one story high, and if of two stories, thereof was so deep, as to 
 shut out the light from the upper rooms. The hall and 
 kitchen formed one apartment, which was open to the timbers 
 of the roof, and, in some cases, was furnished with a louver 
 and a window, that could be closed with a shutter. When 
 these houses had a separate sleeping apartment, old and young 
 occupied it, and several reposed in one bed. Servants slept on 
 the kitchen floor. Cottages had neither louver nor loupe, and 
 the inmates slept round the fire. 
 
 The strongholds which were built about the time of the 
 conquest, were several stories in height, and their roofs being 
 used as a terrace for defence, the central hearth and louver 
 were impracticable. The necessity of providing some exit for 
 the smoke seems to have stimulated invention, and, accordingly, 
 we find the germs of the modern fire-place and chimney in 
 one of these strongholds. In the great guard-room of Conis- 
 borough Castle, erected in or near the Anglo-Saxon period, is 
 
 * On the History and Art of Warming and Ventilating Rooms and 
 Buildings, &c v by Walter Bernan, Civil Engineer. 2 vols. London, 
 1845. We take this opportunity of acknowledging our obligations to 
 these useful and instructive essays, in which the writer has collected a 
 large store of materials on the subject of warming and ventilation, and 
 the " progress of personal and fire-side comfort." To any one who de- 
 sires to study the subject in detail, these volumes will prove acceptable. 
 
FIRST USE OP THE CHIMNEY. 
 
 59 
 
 a large fire-hearth. The mantel is supported by a wide arch, 
 with two transom stones running under it ; the back of the 
 fire-place, where it joins the hearth, is in a line with the walls 
 of the room, and the recess at the mantel is formed by the 
 back of the fire-place sloping outwards, as it rises into the 
 thickness of the wall, until it reaches a loop-hole on the out- 
 side, where the smoke finds an exit. Fig. 6 is an elevation 
 and section of this fire-place, in which *'*& c, 
 
 A is the floor of the room, E the man- 
 tel, and c the loop-hole. 
 
 In other castles erected about the 
 same period, the hearth was formed 
 in the thickness of the wall, and the 
 conical smoke tunnel ended in a loop- 
 
 r 1 I i it -car 
 
 hole, as at Conisborough Castle. 
 
 Fig. 7. 
 
 Fig. 7 is another elevation 
 and section of these an- 
 cient contrivances for 
 carrying off the smoke. 
 It is from Rochester 
 Castle. In the old 
 palace at Caen, which 
 was inhabited by the 
 conqueror while he was 
 Duke of Normandy, 
 the great guard chan - 
 ber contains two spa- 
 cious recessed fire- 
 
60 FIRST USE OP THE CHIMNEY. 
 
 hearths in the north wall, still in good preservation, from 
 which the smoke was carried away in the same manner as in 
 the above examples. 
 
 The transition from these contrivances to the common 
 chimney would seem to be easy; but history has failed to 
 record the inventor, or to define the place where the chimney 
 was first used. Chimneys seem to have been common at 
 Venice before the middle of the fourteenth century. An in- 
 scription over the gate of the school of Santa Maria della 
 Carita states, that in 1347, a great many chimneys were 
 thrown down by an earthquake, a fact which is confirmed by 
 John Villani, who refers the event to the evening of the 
 25th of January. Chimneys had also been in use at Padua 
 before 1368, for in that year Galeazo Gataro relates, that 
 Francisco da Carraro, lord of Padua, came to Rome, and find- 
 ing no chimneys in the inn where he lodged, because at that 
 time fire was kindled in a hole in the middle of the floor, he 
 caused two chimneys, like those that had been long used in 
 Padua, to be constructed by the work-people he had brought 
 with him. Over these chimneys, the first ever seen in Rome, 
 he affixed his arms, which were remaining in the time of 
 Gataro. Winwall House, in Norfolk, which has been described 
 as the most ancient and perfect specimen of Norman do- 
 mestic architecture in the kingdom, has not only recessed 
 hearths, but flues rising from them, carried up in the external 
 and internal walls. Now, if Winwall House really be an 
 Anglo-Norman edifice, its chimneys must have been built in 
 the twelfth century, and, consequently, the claim of the 
 Italians to the invention cannot be supported. The chimneys 
 at Kenilworth and Conway were also probably erected anterior 
 to the date of those on which the Italians rest their claim. 
 Leland, also, in his account of Bolton Castle, which he says 
 was "finiched or Kynge Richard the 2 dyed," notices the 
 chimneys. "One thynge I muche notyd in the hawle of 
 Bolton, how chimeneys were conveyed by tunnells made on 
 the syds of the walls betwyxt the lights in the hawle, and by 
 
THE ANDIRON. 61 
 
 this means, and by no covers, is the smoke of the harthe in 
 the hawle wonder strangely conveyed." 
 
 It is not our duty to trace the further history of the 
 chimney, nor to notice the methods by which the chimney 
 shaft became so prominent and beautiful a feature in buildings 
 during the reigns of the Tudors. It is sufficient to remark, 
 that when once introduced in England, the merits of chimneys 
 were soon appreciated, for we find it stated, that in the reign 
 of Queen Elizabeth, apologies were made to visitors if they 
 could not be accommodated with rooms provided with chim- 
 neys, and ladies were frequently sent out to other houses, 
 where they could have the enjoyment of this luxury, for such 
 it must be called at this period, when the poorer class of 
 houses. was not yet furnished with it. 
 
 Wood was the ordinary fuel till the seventeenth century, 
 and this was burnt on the capacious hearth, the logs being 
 
 Fig. 8. 
 
 confined within the two standards (Fig. 8) of the andiron, their 
 ends resting on the billet bar, for the purpose of admitting the 
 air below them, and thus promoting combustion. For the 
 large kitchen fire, the standards and billet bars were very 
 strong and massive, but usually quite plain. In the hall, that 
 ancient seat of hospitality, they were also strong and massive, 
 to support the weight of the huge logs ; but the standards 
 were kept bright, or ornamented with brass rings, knobs, 
 rosettes, heads and feet of animals, and various grotesque 
 
62 THE DOMESTIC HEARTH. 
 
 forms. In kitchens, and in the rooms of common houses, the 
 andiron, as its name implies, was of iron j but in the hall, the 
 standards were of copper or brass, and sometimes of silver. 
 The spacious receptacle was furnished with seats on each side 
 of the hearth, and the snug chimney corner was the post of 
 honour. When the whole family assembled to enjoy a leisure 
 hour, it was round the hearth that they sat ; with it was 
 associated their ideas of domestic comfort and conviviality, 
 and the word hearth became synonymous with home. In some 
 of our rural districts, the custom is still retained of the whole 
 family sitting under the capacious chimney-breast, and it is an 
 honoured custom which we hope may long continue to exist. 
 
 In smaller rooms, where the fire was made in a wide and 
 deep recess, each standard was fixed into the back of the 
 hearth by a lateral bar. Thus in Figs. 9, 10, and 11, which 
 
 Figs. 9, 10, 11. 
 
 JL 
 
 represent the andirons in the hall at Vicars Close, Wells, 
 will be seen the standards, the billet bar, and the reredos or 
 
PREJUDICES AGAINST COAL. 63 
 
 hob, which in deep recesses brings the fire now into the room. 
 When the hearth was of moderate size, the andiron was 
 moveable.* 
 
 So long as wood existed in abundance, coal was not sought 
 after for the purposes of domestic fuel j it was supposed that 
 the fumes of coal had a peculiarly corrupting effect upon the 
 air, and were most injurious to health. Its value, however, 
 was appreciated by brewers, dyers, smiths, and others, whose 
 occupations lead to the consumption of a large quantity of 
 fuel, and towards the close of the thirteenth century, coal was 
 imported into London from Newcastle, for the use of those 
 trades. In 1306, however, parliament petitioned the king to 
 prohibit the use of the noxious fuel in the city. A royal pro- 
 clamation was accordingly issued, prohibiting the use of coal, 
 and as this failed in its effect, a commission was issued for the 
 purpose of ascertaining who burned sea- coal within the city 
 and its neighbourhood, and to punish them by fine for the first 
 offence, and by the demolition of their furnaces if they per- 
 sisted j but even these severe proceedings failed to put down 
 the nuisance. A law was, therefore, passed, making the 
 burning of sea-coal within the city a capital offence, and per- 
 mitting its use only in the forges of the neighbourhood. In 
 the reign of the first Edward, a man was tried, convicted, and 
 executed, for burning sea-coal in London. Even in districts 
 where coal abounded, it was not used as a domestic fuel, for 
 we read that in 1349, in the religious house at Whalley, peat, 
 with a very little wood, was the only fuel used. 
 
 So deeply rooted was the prejudice against coal, that it was 
 not until the commencement of the seventeenth century that 
 its use became more general. Ladies had an idea that a coal 
 fire injured their complexions, and they would not even enter 
 a house or room where the obnoxious fuel was used; nor 
 would they even partake of meat which had been roasted at a 
 
 * On the mantel shelf is a scroll, bearing an inscription, which solicits 
 the prayers of the Vicars in favour of Sir Richard Pomroy, and expresses 
 .solicitude for the safety of his soul. 
 
0* IMPROVEMENTS IN FIRE-PLACES. 
 
 coal fire. When Ben Jonson had to entertain a party of 
 guests at his house, he warmed his room with a charcoal fire ; 
 but, on ordinary occasions, he used coal, for we find that, on 
 more than one occasion, his flue caught fire from an accumu- 
 lation of soot. 
 
 In an inventory, dated 1603, of the goods of Sir Thomas 
 Kytson, at Hengrave Hall, in Suffolk, mention is made of " a 
 cradell of iron for the chimnye to burne sea-cole with," and 
 also " j fier shelve made like a grate to seft the sea-cole with." 
 The cradle here mentioned was probably nothing more than a 
 few bars bent into a semicircle, and fastened into the upright 
 wall over the hearth. 
 
 There was, doubtless, good reason for the objections of our 
 ancestors to the use of sea-coal, for the chimney fire-places 
 were usually made in the form of a large square recess, and the 
 breast of the chimney was of the same size as the recess itself. 
 In order to rid sea-coal of its noxious sulphurous vapour, 
 Sir John Racket and Octavius de Strada proposed, in 1626, to 
 convert the coal into coke, and thus make it as agreeable a 
 fuel for chambers as wood and charcoal. A patent was ob- 
 tained for the purpose, but the speculation did not succeed, as 
 the vapour given off by the coke was found to be nearly as 
 unpleasant as that from coal. 
 
 About this time, a great improvement was made in France 
 in fire-places. Louis Savot, in his Treatise on Architecture, 
 remarks that large rooms only are free from smoke, and that 
 when fires are made in small apartments, a door or a window 
 had to be left open, or else the air came down the wide flue, 
 and drove the smoke into the room. To correct this defect, 
 he raised the hearth about four inches, and lowered the mantel, 
 so as to make the opening of the fire-place about three feet high. 
 The width between the jambs was reduced to three feet ; the 
 jambs from the mantel were to be carried up sloping to the 
 waist, or where the flue begins to be of uniform width, and the 
 opening of the fire-place was formed like an arch. But, where 
 the fire-place could not be conveniently altered, Savot perfo- 
 
SAVOTS FIRE-PLACE. 
 
 rated with small holes a plate of iron, whose width and length 
 was nearly equal to the hearth, and this was fixed three inches 
 above the tiles of the common hearth. On this perforated 
 plate he placed a grill de fer of the same length as the billets 
 to be burned, and raised nine inches above the plate ; the 
 wood was placed on the grate, the charcoal on the perforated 
 plate, and the hearth received the ashes ; the air, rising through 
 the small holes, made the charcoal burn briskly, and this so 
 much assisted the burning of the wood, that a rapid draught 
 up the chimney was established, and smoke prevented. 
 
 In Savot's description of the fire-place used to heat the 
 " Cabinet des Livres," at the Louvre, we have the first 
 recorded attempt at combining the cheerfulness of an open 
 fire with the economy of an enclosed stove. Fig 12 is a front 
 
 Fig. 12. Fig. 13. 
 
 view, and Fig. 13 a vertical section of this ingenious contri- 
 vance. The hearth was a thick iron plate placed above the 
 old hearth, with an interval, n, of three inches between them. 
 The two sides, or covings of the fire-place, were also formed 
 of thick iron plates, placed three inches from the jambs. The 
 space, n, at the back, and the spaces at the sides, communi- 
 cated with the space, n, under the hearth ; two pipes, or 
 channels, i, communicating with these hollow spaces, opened 
 
SIR JOHN WINTERS FIRE-PLACE. 
 
 - u - 
 
 into the room at c, as shown by the dotted line in the section; 
 these spaces could be closed at pleasure. When the fire was 
 burning, the iron hearth, and the plates [which formed the 
 sides or covings, and the back, became very hot. The cold 
 air at the floor, entering by the openings at a, into the space , 
 was heated by the hearth, and rising into the spaces at the 
 back and sides, had its temperature further increased ; it then 
 entered the channels i, and escaped at c, thus diffusing an 
 agreeable warmth over the whole room. 
 
 About the year 1658, the project for burning coke, instead 
 of coal, was revived by Sir John Winter, who invented an 
 improved fire-place for the purpose. The cradle, or fire-cage, 
 was placed on a box about eleven inches high, in the front of 
 which was an opening, o (Fig. 14), fitted with a door, which 
 was always kept closed, except when the 
 ashes were removed. A pipe, a, in- 
 serted into the side of the box, com- 
 municated with the external air, at a 
 level of two or three feet below the bot- 
 tom bars of the fire-cage ; this pipe 
 could be closed at pleasure by a valve. 
 When the coke, or charked coal in the 
 fire-cage, did not burn well, the valve 
 was opened, and the air from the outside 
 rushed in a strong current into the box, 
 and, by its powerful blast, soon roused 
 up the fire ; the valve was then closed, and all communication 
 with the external air was thus cut off. The flue was closed 
 with an iron plate or register, that moved on a hinge. It had 
 an opening, c, 8 inches square, for carrying the smoke into 
 the chimney, and this was found large enough for a fire-place 
 of any dimensions. This ingenious contrivance does not seem 
 to have succeeded, although both it and the arrangement 
 described by Savot have, with slight variations, been brought 
 forward several times within the last three quarters of a cen- 
 tury, and patented as notable inventions. 
 
 In 1678, Prince Rupert invented a fire-place, so contrived 
 
PRINCE RUPERTS FIRE-PLACE. 
 
 67 
 
 Fig. 15. 
 
 that the draught took a downward direction before entering 
 the flue, as shewn in Fig. 15, in which 
 a x is a wall built at a distance of 10 
 inches from the back of the hearth 
 recess, and carried up to the mantel, 
 where it is terminated by the wall x, 
 thus completely closing all communi- 
 cation between the flue and the room. 
 An opening, a, is made in this wall, 
 10 inches high, and of the same width 
 as the length of the grate, and its 
 sill is 2 inches above the top rib of 
 of the grate. Fixed within the chim- 
 ney is a plate of iron, i, placed perpen- 
 dicularly, so as to divide it into two 
 equal parts. To the upper edge of this 
 plate is hinged an iron door, c, as long as the chimney is 
 wide, and this door can be brought into the position c, or 
 into that indicated by the dotted lines at e. The fuel grate 
 stands on the hearth, and is placed nearly in a line with the 
 wall of the room. At the back of the ash-pit is a brick that 
 closes the aperture through which the soot is removed. When 
 the fire is first lighted, the smoke door, c, is pushed back, and 
 when the draught is once established, this door is drawn for- 
 ward, and the smoke being thus prevented from flowing 
 upwards, reverberates downwards, and passes the lower edge 
 of the division plate, i, and rises between it and the back of 
 the hearth into the chimney flue. In boisterous weather, or 
 with such a fire-place, in an upper room, where the chimney 
 is short, another iron door, r, is hung under the edge of the 
 mantel, in front of the fire-place, and extending the whole 
 width of the opening. Its breadth varies according to circum- 
 stances, but it is made so as to reach within two inches of the 
 upper bar of the fire-grate, when hanging in the position shewn 
 by the dotted lines at s. This converts the fire into a furnace, 
 and the room will, in such case, be " warmer than it would be 
 with a fire four times the size made in a common cradell." 
 
68 
 
 THE FIRE-CLOTH. 
 
 When the smoke flows regularly through the aperture a, this 
 door is thrown back out of use, as at r. In some cases, the 
 ordinary fire-board or fire-cloth was used instead of this door. 
 
 "The fire -cloth," says Mr. Bernan, "was a common append- 
 age to a fire-place, particularly where wood was burned, 
 for then the flue was large, the hearth wide and low, and the 
 mantel high ; when the chimney smoked in certain winds 
 only, the cloth was suspended, when wanted, from each corner 
 of the mantel-piece. But when the disease was unremitting, 
 the curtain was fixed by rings, running on a rod that went 
 across the fire-place ; when not used, it was drawn to one 
 side, like the curtain of a cottage window ; very often the 
 fire-cloth was contrived to be drawn up like a modern Venetian 
 blind, and made so deep, as to reach from the mantel to the 
 hearth, and serve the office of a fire-board, when there was no 
 fire in the yawning chimney. The first variety of smoke 
 cloth was seldom more than fifteen inches deep, and was fre- 
 quently made of painted leather; but in good houses, the sus- 
 pended fire-cloths were usually of damask and tapestry. 
 None of these contrivances are yet extinct." 
 
 In 1 680, a stove was exhibited at the fair of St. Germains, 
 near Paris, in which the smoke not only descended, but was 
 also consumed. It is formed of hammered iron, and stands 
 on the floor of the room. The fuel, wood, or coal, is contained 
 in a vase, c (Fig. 16), with a grating at o, and this vase is placed 
 
 Fig. 16. 
 
DESCENDING FLUE. 
 
 69 
 
 on a box or cylinder o, from which a pipe, i, is carried into a 
 flue, which has no communication with the hearth recess, nor 
 with the air, except at the top, above the roof. The vase 
 being filled with fuel, some dry brushwood is placed upon it. 
 The upper part of the pipe, i, is then heated by a lamp, or hot 
 iron, in order to establish a current of air from the cylinder o, 
 which current passes down through the fuel in the vase. A 
 piece of lighted paper is then placed on the brushwood, and 
 the downward current carries tfie flame downwards, first 
 igniting the wood and then the coals, and consuming the 
 smoke in descending. The products of combustion thus 
 carried into the cylinder, a, rise through the pipe, i, into the 
 chimney. The descending current may be made evident by 
 holding a flame over the vase, and it will be drawn down- 
 wards. Justel, who described this arrangement to the Royal 
 Society in 1681, says, that "the most fceted things, matters 
 which stink abominably when taken out of the fire, in this en- 
 gine make no ill scent, neither do red herrings broiled thereon. 
 On the other hand, all perfumes are lost, and incense makes 
 no smell at all when burned therein." An improved edition 
 of this stove was made by Dr. Franklin. 
 
 A very economical method of heating two rooms by one 
 fire is described by Savot. A plate of iron is made to sepa- 
 rate the fire-places of the two adjacent 
 rooms. A fire made on the hearth, a 
 (Fig. 17), heats the plate, and this, in its 
 turn, by its radiation, warms the air in the 
 adjacent room, e, as effectually as a stove 
 would do, provided its flue, i, is properly 
 closed. Or if the second room have no 
 chimney, it may still be warmed by making 
 an opening in the wall, at the back of the 
 fire-place, and closing it with an iron plate. When Dr. Franklin 
 was in Paris, he saw an example of this contrivance, and esti- 
 mated it highly. 
 
 In all these early contrivances there is much ingenuity, and 
 
 Fig. 17. 
 
70 CARDINAL POLIGNAC'S 
 
 we bring them forward thus prominently, because they are 
 really the legitimate ancestors of many reputed modern in- 
 ventions, whose authors are either ignorant of, or have failed 
 to acknowledge, their legitimate descent therefrom. Patentees 
 would often be spared much anxiety and expense, if they 
 would condescend to study the subject to which their in- 
 vention refers, before they introduce to the public a contrivance 
 which may have been as well, if not better, done a long time 
 before. Inventions, whether in the fine arts or in the useful 
 arts, require genius often of a high order ; and although it is 
 not expected that every inventor should have the genius of 
 "Watt, it is at least required that they should possess some of 
 his method of patient research. 
 
 But there is one writer, whose inventions have especially 
 served as the type of many a modern fire-place, and at the 
 time of its publication in 1713, shewed a great and sudden 
 advance in the art of warming apartments. The author of 
 the treatise referred to is no less a man than the Cardinal 
 Polignac, who, under the assumed name of Gauger, published a 
 treatise, entitled "La Mechanique du Feu, on VArt (Pen aug- 
 menter les efets et d'en diminuer la depense, contenant le Traite 
 de Noumlles Cheminees qui echauffent plus que les Cheminees 
 ordinaires, et qui ne sont point sujettes a fumer" This treatise 
 was reprinted at Amsterdam in 1714, and a translation of it, 
 by Dr. Desauguliers (from which we are about to quote), was 
 published in London in 1716. 
 
 In the preface, the author has some sensible observations on 
 the subject of warming and ventilation. After remarking 
 that persons who judge of the value of machines by their 
 complication, will not find his inventions to their taste, he 
 bestows a compliment on those who estimate " such devices 
 from the simplicity of their construction, and the facility of 
 their execution," and then proceeds thus : " A plate of iron 
 or copper bowed or bended after such a manner as is not at all 
 disagreeable to the sight ; a void behind, divided by certain 
 small iron bands or partition plates, forming several spaces 
 
IMPROVED FIRE-PLACES. 71 
 
 that have a communication one with another; a little vent 
 hole in the middle of the hearth, a register plate in the upper 
 part of the funnel; and for some shafts, a capital on the top, 
 make up the whole construction and workmanship of our 
 modern chimney. Now can there be anything more simple 
 or plain, or more easy to execute 1" 
 
 " To be able to kindle a fire speedily and make it, if you 
 please flame continually, whatever wood is burning, without 
 the use of bellows ; to give heat to a spacious room, and even 
 to another adjoining, with a little fire ; to warm one's self at 
 the same time on all sides, be the weather ever so cold, with- 
 out scorching ; to breathe a pure air always fresh, and to such 
 a degree of warmth as is thought fit ; to be never annoyed 
 with smoke in one's apartment, nor have any moisture therein ; 
 to quench by one's self, and in an instant, any fire that may 
 catch in the tunnel of a chimney ; all these are but a few of 
 the effects and properties of these wonderful machines, not- 
 withstanding their apparent simplicity. Since I used this sort 
 of chimney, I have not been troubled one moment with smoke, 
 in a lodging which it rendered before untenable as soon as a 
 fire was lighted; I have always inhaled, even during the 
 sharpest seasons, a fresh air like that of the spring. In 1709, 
 water that froze hard everywhere else very near the hearth, 
 did not congeal at night in my chamber, though the fire was 
 put out before midnight ; and all that was brought thither in 
 the day soon thawed, neither did I ever perceive the least 
 moisture in winter, not even during thaws." 
 
 The treatise opens with the following remark : " It seems 
 that those who have hitherto built or caused chimneys to be 
 erected, have only taken care to contrive in the chambers 
 certain places where wood may be burnt, without making a 
 due reflection that the wood in burning ought to warm those 
 chambers, and the persons who are in them ; at least, it is 
 certain that but a very little heat is felt of the fire made in 
 the ordinary chimneys, and that they might be ordered so as 
 to send forth a great deal more, only by changing the disposi- 
 
72 
 
 PARABOLIC JAMBS. 
 
 Fig. 18 
 
 tion of their jambs and wings." The methods by which a fire 
 may communicate its heating effect to a room, are correctly 
 stated to be by radiation, by reflection, and by conduction. 
 Now as radiant heat is reflected according to the same law as 
 light, i. e., the angle of incidence is equal to the angle of reflec- 
 tion, it follows that, in a fire-place with straight jambs, very 
 few of the rays are reflected into the room. Thus, suppose a 
 
 fire, /(Fig. 18), to be made 
 in an ordinary chimney, A B, 
 b a, of which the jambs, A B, 
 a b, are parallel, the ray of 
 heat, / G, will be reflected 
 back in M ; the ray / H 
 ^- p upon itself in/; the ray /i 
 
 in N ; and the ray/L in p; and this is the only ray that can 
 be reflected into the chamber, the others being to the back, or 
 up the chimney, or among the fuel, and contribute in no way 
 to the useful heating effect of the fire. In cases, however, 
 where the jambs are formed of plaster, there is not even this 
 reflection, for the heat, falling upon the dull surface, is absorbed. 
 The author then describes what ought to be the correct form 
 of the jambs : " Geometricians," he says, " are sensible that 
 all radiuses which set out from the focus of a parabola and fall 
 upon its sides, are reflected back parallel to its axis. If, there- 
 fore, you take on the bottom 
 of a chimney hearth, A B, b a 
 (Fig. 19), a length, c c, equal 
 to that of the wood designed 
 to be burnt, for example, of 
 half a log or billet, which, at 
 Paris, is 22 inches; from the 
 points c c, let fall the perpendicular c D, c d, which may be 
 the axis of two semi-parabolas, whereof c c are the vertices 
 and A a (the distance between which is the breadth of the 
 chimney), each of them one of their points ; that done, you 
 are to line with iron or copper plates the two parabolical sides 
 
 Fig. 19. 
 
 in: 
 
METHOD OF SUPPLYING AIR. 73 
 
 A C, a c, of the chimney, and make the lower part of the con- 
 cave parallel to the horizon, and as large as it can be, only 
 leaving ten or twelve inches for the aperture of the chimney 
 funnel. By this arrangement, as much of the heat as can be 
 will be reflected, for all the rays of heat from the focus F / of 
 each semi-parabola, as fg, fh,fi,fl, &c., will be reflected 
 back parallel to the axis c d in m, n, o, p, and consequently, 
 pass into the room. So also, all those rays, E H i, which are 
 not reflected back parallel to the axis, will nevertheless be 
 reflected into the chamber or very nearly so. Besides 
 this, the jambs being so much nearer the fire than is 
 usual, will soon become heated, and reflect a larger number of 
 rays." 
 
 All draughts in the room towards the fire were avoided, by 
 introducing a soufflet, or blower, already described in Savot's 
 and Winter's stoves (Figs. 12 and 14). Its opening was situated 
 at z (Fig. 19), in the centre of the hearth, 10 or 12 inches below 
 the plate on which the fuel was burned, and communicated with 
 the open air by a channel from 4 to 6 inches square. The 
 opening in the hearth was furnished with a metal frame, on 
 which was hinged a trap door, or valve, opening upwards; 
 the upper surface of this valve was furnished with a button, 
 which could be grasped with the tongs, and a small bolt 
 beneath could then be drawn back, or closed with the button 
 with which it was connected. The sides of the valve were 
 formed by two thin sectors of iron, which guided the 
 current of air through the channel, and confined it within 
 narrow limits. Two springs in the frame pressed against the 
 sector sides, and kept the valve open at any desired angle ; of 
 course, when the valve was shut and bolted, there was no 
 current. 
 
 A number of complicated varieties of fire-place are described 
 in this treatise, all of which are furnished with parabolic jambs 
 and the soufflet ; but the back, the jambs, the hearth, and 
 the mantel, were also made hollow, for the purpose of 
 
 E 
 
74 
 
 DETAILS OF THE 
 
 Fig. 20. 
 
 pouring a copious supply 
 of heated air into the apart- 
 ment. These hollow spaces, 
 named caliducts or mean- 
 ders, are in one arrange- 
 ment (Fig. 20) formed by 
 perpendicular divisions. In 
 another variety (Fig. 21) 
 they are horizontal. In 
 this variety the hearth is also hollowed out, and divided 
 
 Fig. 21. 
 
 regulated 
 
 into a series of square 
 spaces. The cold air enter- 
 ing at a, follows the direc- 
 tion of the arrows, and 
 escapes into the room at x ; 
 c is the hearth, m the 
 smoke flue, and d s i the 
 caliducts. 
 
 The supply of hot air, 
 by a valve in the air- 
 
 into the room was 
 
 channel, formed on the principle of Papin's four-way 
 
 cock. A small cylinder, x (Fig. 22), moved within another 
 
 Fig. 22. 
 
 cylinder which was fixed. The 
 revolving cylinder had two aper- 
 tures, o o, and the fixed cylinder 
 three apertures. The axis of the re- 
 volving cylinder passed through the 
 cover of the fixed cylinder, and had 
 a small leyer or needle attached to it, 
 by means of which the cylinder was turned by the hand into 
 certain positions marked on a small dial. When the apertures, 
 o o t in the revolving cylinder coincided with those in the 
 fixed cylinder, the external air from the channel was admitted 
 into the caliducts in the chimney back : by turning the revolv- 
 ing cylinder into another position, the cold air was excluded 
 
POLIGNAC FIRE-PLACE. 
 
 75 
 
 from the caliducts, and admitted directly into the apart- 
 ments. 
 
 The cylinder could also be placed so as to shut off the cold 
 air both from the caliducts and from the room. In this way 
 the air of the room could be tempered according to the wants 
 and feelings of the occupants. 
 
 The arrangement to which the Cardinal gave his decided 
 preference, is represented in the following figures. Fig. 23 
 
 Fig. 23. 
 
 Fig. 24. 
 
 represents a horizontal section 
 of the fire-place, and Fig. 24 
 a vertical section. The hollow 
 metal case forming the back of 
 the chimney is divided into three 
 or more caliducts, p q r, each 
 four inches wide and six inches 
 and three quarters broad, placed 
 about an inch from the back 
 wall of the hearth recess, with 
 its lower edge, m, about two 
 inches above the surface of the 
 iron bottom plate or hearth, a. 
 The jambs, w, lined with iron 
 or brass plates, are formed in a 
 parabolic curve, and solid at the 
 back. The channel, x, conduct- 
 ing the external air into the 
 E 2 
 
76 
 
 DETAILS OF THE 
 
 caliducts, is nine inches on the side; and the blower, c, fur- 
 nished with its valve, forms an aperture three inches long and 
 two inches and a half wide, but instead of being supplied 
 with air from the outside by a separate channel, the air is de- 
 rived from the channel, z. The air valve, a?, is placed at the 
 junction of the cold air channel, with the caliducts j and the 
 aperture, z, through which the warmed air enters the room, 
 is fitted with a sliding valve, to close the warm air aperture. 
 
 The action of this apparatus is simple. The small wood on 
 the hearth being lighted, and the valve of the soufflet, c, lifted 
 up, the logs soon begin to kindle into a good fire ; the smoke 
 and flame rise into the space between the back, p q r, and the 
 wall of the hearth, and, after heating the iron back of the cali- 
 ducts, escape into the flue. In the meantime, the other face 
 towards the room, is also quickly heated by the flame and 
 smoke. The valve, o, being adjusted to admit the external air 
 into the first caliduct, it flows thence into the second and third 
 caliducts, receiving fresh accessions of heat in its progress, until 
 it escapes at z, into the apartment, which it speedily warms. 
 
 For large apartments, these fire-places may be erected in the 
 middle of the room, and two may be set back to back, with 
 one series of caliducts for both, so that the air will be heated, 
 whether the fire be kindled in one or both. When kindled in 
 both, the heating effect will, of course, be greatly increased. 
 So, also, two adjoining rooms may be heated by one fire, 
 provided the hearth recesses are placed back to back ; for, by 
 making a fire in one room, the heated air from the caliducts 
 may be discharged into the other ; or by carrying a pipe from 
 the caliducts through the wall into an adjoining room, .or 
 through the ceiling into an upper room, an agreeable and a 
 sufficient warmth may be distributed. 
 
 All subsequent writers of repute have acknowledged the 
 great merits of the Cardinal's treatise. Franklin admitted 
 the great assistance it had afforded him ; and the improve- 
 ments in stoves, so successfully introduced by Count Rumford, 
 are all similar in principle to those suggested by this book. It 
 
POLIGNAC FIRE-PLACE. 77 
 
 will be obvious how very superior is the Polignac Jire-place 
 (as the arrangement just described is named), to those on the 
 common construction, from the following remarks by Mr. 
 Bernan: " The external air, in passing through the caliducts, 
 being raised to a temperate heat, and spreading itself 
 throughout the chamber, a person in the coldest weather 
 is surrounded with warm air, and heated, without going near the 
 fire, on all sides at once ; while, from the construction of the 
 hearth, he enjoys the radiant heat in greater perfection than 
 in the common chimneys. The large body of air, constantly 
 flowing into the room from the caliducts, prevents all chink 
 minds or dangerous disease-bringing currents ; and as there is 
 as much impure air withdrawn as there is fresh warm air 
 admitted, an unceasing salutary ventilation goes on, from the 
 time the fire is lighted until it is extinguished ; so that a person 
 may always remain in a room thus warmed, and breathe as 
 pure an air as if he were in the fields." 
 
 The Polignac fire-places were constructed for the combus- 
 tion of wood fuel. Dr. Desaguliers modified them so as to 
 admit of coal being burnt, and, in conjunction with an archi- 
 tect, manufactured them, and erected a considerable number 
 in London. For a time the comforts and convenience, as 
 well as economy of these fire-places, were appreciated, and they 
 were rising rapidly into favour ; but, unfortunately, an outcry 
 was raised against them by Mr. Hauksbee and some other 
 scientific opponents of Dr. Desaguliers, who declared that 
 these fire-places " burnt the air, and that burnt air was fatal 
 to animal life." This was a death blow to the Doctor's new 
 fire-places, and many years afterwards, when referring to the 
 subject, he mournfully remarks, "As I took so much pains 
 and care, and was at some expense to make this management 
 of air useful, I can't help complaining of those who endea- 
 voured to defeat me in it." 
 
 In 1745, Dr. Franklin introduced a fire-place, which he 
 named the Pennsyhanian stow, in which Prince Rupert's 
 descending flue was ingeniously combined with the Cardinal 
 
78 SMOKE CONSUMING GRATE. 
 
 Polignac's caliducts. This stove was constructed for burning 
 wood, but in 1753, Mr. Durno adapted it for burning of coals, 
 and sent one of his stoves to London for a model. The fuel 
 box was 15 inches wide, 5| inches deep, from the grating to 
 the top bar, 5 J inches from front to back. This kept a room, 
 14 feet square, at a temperature of between 60 and 64 during 
 13 hours, with the consumption of only one peck of coals, at a 
 time when the external temperature was 28 or 4 below 
 freezing. 
 
 A simple, but highly ingenious grate, in which the burning 
 fuel was made to consume its own smoke, was also one of the 
 many original contrivances of Franklin. It consisted of a 
 circular fire-cage, (Fig. 25,) about a foot in 
 diameter, and from 6 to 8 inches wide 
 from front to back ; the back is of plate 
 iron, and the front filled with bars, of 
 which the three middle are fixed and 
 the top and bottom moveable, and 
 either one may be drawn out for the 
 purpose of filling the grate with fuel. 
 The fire cage turns upon axes, supported 
 by a crochet, fixed on a stem, which 
 revolves upon a pivot fixed to the hearth. The fire is 
 lighted by withdrawing the upper bar and then placing 
 wood and coals in the cage, as in a common grate, 
 the bar is then replaced. So also in adding fresh fuel, 
 the upper bar is removed and then replaced. When the 
 grate is first lighted, a quantity of thick smoke is emitted by 
 the fuel ; but, as soon as it begins to burn well, the cage is 
 turned round on its axes, so that the burning coals at the 
 bottom shall occupy a position at the top. The whole is then 
 turned round on the pivot, so as to bring the bars again in 
 front; by this arrangement the fresh coals below the lighted 
 fuel will gradually ignite, and their smoke, having to pass 
 through the fire above them, will be entirely consumed. In 
 this way the combustion is perfect, or nearly so, and this 
 
THE RUMFORD STOVE. 
 
 79 
 
 economy of fuel is accompanied by a much greater heating 
 effect ; little or no soot is deposited, for all the combustible 
 matter of the fuel is converted into heat. For want of some 
 such contrivance, a very considerable portion of our fuel is 
 wasted by our open fires under the best management. Soot is 
 very inflammable, and one pound of it gives as much, if not 
 more heat, than one pound of coal ; and the quantity of soot 
 which lines our chimneys is very inconsiderable, compared with 
 that which escapes unconsumed at the chimney top, and fills 
 the neighbourhood with Hacks, and, returning into our houses 
 through the open windows, makes the furniture dirty, or, 
 entering our lungs, offers an impediment to free respiration. 
 Another advantage of the revolving grate is, that it may be 
 turned into any position, so as to radiate its heat in one 
 direction rather than another, and, by placing the bars in a 
 horizontal position, a teakettle, or other cooking utensil, may 
 be conveniently set on it. 
 
 Count Rumford deserves honourable mention as an improver 
 of grates, and an economiser of fuel. The Rumford stove has 
 made his name familiar among all classes, and is so well known, 
 that a description is unnecessary. The Count's essential im- 
 provement consisted in contracting the area of the fire-cham- 
 ber, and placing a flat surface in each interior angle, as in the 
 plan Fig. 27, so as to reflect that portion of heat into the room, 
 Fig. 26. which in the old square chambered grates 
 escaped up the chimney. The throat of the 
 chimney was also greatly reduced in size, and 
 the breast-work, a (Fig. 26), rounded off, in 
 order to afford less obstruction to the ascent 
 of the smoke ; when the chimney required 
 sweeping, the plate or flagstone, b, could be 
 removed so as to open the throat, and be re- 
 placed after the operation. According to 
 Rumford, in order to obtain the greatest 
 effect from the fuel, the sides of the fire- 
 place ought to be placed at an angle of 1 35 with the back of 
 the grate, or, which is the same thing, at an angle of 45 with 
 
80 THE RUMFORD STOVE. 
 
 a line drawn across the front of the fire-place. (See 
 Fig. 27. Fig. 27.) These angular 
 
 covings were not to be of 
 iron, but of some non-con- 
 ducting substance, such as 
 fire-clay, and polished with 
 black-lead. He objected to 
 circular covings, on the 
 
 ground that they produced eddies or currents, which would 
 be likely to cause the chimney to smoke; and he also 
 objected to the old form of registers or metal covers to the 
 breast of the chimney, for the same reason ; and also because 
 by their sloping upwards towards the back of the fire-place, 
 they caused the warm air from the room to be drawn up the 
 chimney, and thus interfered with the passage of the smoke. 
 These registers are now arranged so as to be lower at the back 
 than at the front of the stove, but they are usually placed too 
 high up. If brought down lower and placed at an angle of 
 45, much of the heat of the fire would be reflected into the 
 room. The Count also greatly diminished the size of the fire 
 grate, and considered the best proportions for the chimney 
 recess to be when the width of the back was equal to the depth 
 from front to back, and the width of the front or opening 
 between the jambs three times the width of the back. 
 
 " Although the best form for register stoves has now for 
 several years past been adopted, the desire for novelty has 
 caused the true principles of construction to be frequently 
 departed from ; and we accordingly find, in the most modern 
 stoves, considerable deviations from these principles. Fig. 28 
 Fig 28 is a section of a register stove, con- 
 
 structed on the best possible plan for 
 diffusing heat into the room. The 
 sides are a right angle of 90, ABC, 
 and the bars, d e, describe a quadrant 
 of a circle, whose radius is just half 
 the length of the side A B. If we now wish to follow Rumford's 
 rule of making the back one-third the width of the front, we 
 
THE CHIMNEY* 
 
 obtain this by taking one-third of the length A B, which will 
 give B/; and then if we draw the line / g, we shall obtain 
 exactly the required dimensions. By this arrangement it will 
 be perceived, that the sides of the stove form an angle of 135 
 with the back ; and all the rays of heat which fall upon these 
 sloping sides, will therefore be reflected into the room, directly 
 in front of the stove in right lines. The falling cover, or 
 register-top should also form an angle of 135 with the back, 
 by which a large portion of heat will be radiated downwards 
 into the room. These proportions, however, cannot well be 
 adopted in stoves of a very large size, as they will be found to 
 throw the stove rather too far back ; but for all moderate 
 sized stoves, no form can be adopted which will produce so 
 good an effect."* 
 
 We think we have now indicated all the various families of 
 open fire-places, at least as far as their principles are concerned. 
 The species are innumerable, and it would be impossible, in 
 our limited space, to give even a list of them. Those who 
 desire further information on the subject, are referred to 
 Mr. Bernan's entertaining little volumes. But as the subject 
 of open fires is closely connected with that of smoky chimneys, 
 it may be useful to introduce a few details respecting this 
 complaint and its cure. 
 
 Science often follows as well as precedes the useful arts. 
 In the former case, she has to correct defects } in the latter 
 case, the progress of those arts depends on her own improve- 
 ment. The invention of chimneys was not a scientific result, 
 but an act of necessity. The first object proposed to be 
 accomplished by them was to discharge into the air the pro- 
 ducts of combustion, instead of allowing them to spread over 
 the apartment. With the huge wood fires of our ancestors, 
 the large hearth recess and the capacious flue did not interfere 
 with the accomplishment of the object proposed ; but as cir- 
 cumstances changed when fire-places were introduced into 
 
 * A Practical Treatise on Warming Buildings by Hot Water, <Cr. 
 By Charles Hood, F.R.S., &c. Second Edition. London, 1844. 
 
 E 5 
 
oJ CAUSE OF THE DRAUGHT 
 
 small rooms, and coal was substituted for wood the arrange- 
 ments which were suited to the baronial hall or kitchen did 
 not apply. Science was unable, or did not condescend, to 
 investigate the subject, and thus the defects of chimneys con- 
 tinued to exist through many generations. One great defect 
 arose from the great capacity of the flue in proportion to the 
 extent of the fire, the heat of which was often insufficient to 
 determine an upward current for carrying off the smoke. It 
 is now a matter of every day experience, that the force of the 
 draught in a chimney is so much the greater as the column of 
 air which passes up it is longer or more heated, or, in other 
 words, the taller the chimney, or the hotter the fire, the more 
 rapid will be the draught. The ascentional force of this 
 current is the difference between the weight of the column of 
 heated air in the chimney, and a column of the surrounding 
 atmosphere of equal height. The draught therefore is in- 
 creased by increasing the perpendicular height of the chimney. 
 Its length in a horizontal direction does not increase, but 
 diminishes the draught, by cooling the air before it gets into 
 the effective part of the flue. The draught is also increased, 
 by making all the air which enters the chimney pass through 
 or very near the fuel ; for when much air gets into the chimney 
 above^he fire, by having a high mantel-piece, the mass of air in 
 the chimney cannot get sufficiently heated. 
 
 It is a law of expansion for atmospheric air and all gases, 
 that they dilate almost equally and very nearly in proportion 
 to the increase of temperature. According to Gay Lussac, 
 1,000 cubic inches of air at the freezing temperature increase 
 in bulk to 1,375 cubic inches at the temperature of boiling 
 water. For an increase of temperature, therefore, from 32 to 
 212, amounting to 180, the increase of volume is 375 parts 
 in 1,000, or -| of the whole bulk ; and since the expansion is 
 uniform, the increase of volume for 1 will be found by divid- 
 ing this by 180, which will give an increase of 20 $ parts in 
 10,000 for 1 of Fahrenheit's thermometer. The recent ex- 
 periments by Magnus and Regnault have thrown a doubt on 
 
IN CHIMNEYS. 83 
 
 the correctness of this result. By methods perfectly indepen- 
 dent of each other, these philosophers have arrived at 0.3665, 
 instead of 0.375, as the true co-efficient for the expansion of 
 atmospheric air. 
 
 Now as this law of expansion applies equally to air in motion 
 as to air in a state of rest, we can thus calculate the amount of 
 dilatation undergone by the column of air in a chimney from 
 the heat of the fire in the grate. But as the heat is constantly 
 varying, so also is the volume of ascending air. The air of 
 the room which passes through the fire and undergoes a che- 
 mical change is intensely heated, and passing up the flue 
 becomes reduced in temperature at every step. The air which 
 rushes into the cavity above the fire becomes also suddenly 
 expanded, rises, and mingling with the heated gaseous pro- 
 ducts of combustion, diminishes somewhat of their temperature, 
 while it augments their bulk. The mean temperature of the 
 heated ascending column may be found by taking the tempe- 
 rature a short distance above the burning fuel, and also at the 
 top of the chimney ; by adding these two results together, 
 and dividing by two, we get the mean temperature, or a near 
 approximation thereto. We are then able to calculate the 
 force of the draught by applying one of those, rules which 
 scientific men have formed for the purpose. The method of 
 calculation proposed by Montgolfier is very simple, and appears, 
 from recent inquiries, to be accurate. It is this : Ascertain 
 the difference in height between two equal columns of air 
 when one is heated to a certain temperature, the other being 
 the temperature of the external air, and the force of the 
 draught, or the rate of efflux, is equal to the velocity that a 
 heavy body would acquire by falling freely through this differ- 
 ence of height. 
 
 Now the space through which a heavy body falls in perpen- 
 dicular height in one second is rather more than sixteen feet ; 
 but by the law of accelerating forces, the velocity of a falling- 
 body at the end of any given time is such as would carry it, 
 in an equal time, through twice the space through which it has 
 
84 HEORY OP THE CHIMNEY. 
 
 fallen in that time ; or the velocity, in feet per second, is 
 equal to eight times the square root of the number of feet in 
 the fall ; or, to the square root of the number obtained by 
 multiplying 64 by the height of the fall in feet. 
 
 When the force of the draught of a chimney is the differ- 
 ence in weight between two columns of air caused by the 
 expansion of one of these columns by heat, the decimal. 00208 
 which represents the expansion of air by 1 of Fahrenheit 
 must be multiplied by the number of degrees the temperature 
 is raised, and this product again by the height of the heated 
 column. Thus if the height of the column is 50 feet, and 
 the increase of temperature 20, we have 20 x. 00208x50 
 =2.08 feet j or 52.08 feet of hot air will balance 50 feet of 
 the cold air ; and the velocity of efflux of the heated column 
 when pressed by the greater weight of the colder column will 
 be equal to 8^2.08=11.54 feet per second. 
 
 The mean temperature of the heated ascending current in 
 a chimney is much greater than 20 above that of the colder 
 column with which it is compared ; but it is most probable 
 that air expands more proportionally at high temperatures 
 than at low ones for equal increments of heat. As the law of 
 expansion for high temperatures has not, as far as we know, 
 been determined, it was thought better to select an example 
 within the range of our knowledge, than to assume a higher 
 temperature, which would more nearly represent the conditions 
 of the case. 
 
 By the same means, the efflux of air, under any given pres- 
 sure, can also be calculated. The pressure being known, we 
 calculate the height of a column of air equal in weight to 
 this pressure. Thus if the pressure be equal to one inch of 
 mercury, water is 827 times the weight of air, and mercury 
 13.5 times the weight of water; therefore 827X13.5= 
 11,164 inches, or 930.4 feet ; and according to the rule 
 8v/930.4=244 feet per second for the velocity of efflux 
 under the pressure of one inch of mercury. 
 
 In these cases, however, there must be an allowance for loss 
 
SMOKY CHIMNEYS. 85 
 
 by friction, which will vary according to the nature and size 
 of the chimney shaft, and also according to the velocity of the 
 air. The retardation of the air by friction, in passing through 
 straight tubes, will be directly as the length of the tube and 
 the square of the velocity, and inversely as the diameter. 
 
 In this way the action of chimneys is brought within the 
 domain of science. There are, however, practical difficulties 
 and special cases which usually come under the pathological 
 treatment of the smoke-doctor ; these may all be resolved by 
 reference to well-known scientific principles, but, unfortunately, 
 the smoke-doctor is not always, indeed very seldom, a man of 
 science. The following cases of smoky chimneys and the 
 method of cure, will include as much as need be said on this 
 subject to the intelligent reader. 
 
 Chimneys may smoke for want of a sufficient supply of 
 air. This is sometimes the case in a new house, where doors 
 and windows fit tightly and accurately, so that scarcely a 
 chink is left for the admission of air. Or if the house be not 
 new, the windows and doors are often listed, sandbags are 
 placed over the junction of the two window-frames, and a thick 
 mat closes the bottom of the door, and even the key-hole is 
 often stopped. It is no wonder that, under such circumstances, 
 the chimney should smoke ; for the air necessary to support 
 the fire must come down the chimney (the only way left for 
 it) instead of passing through the fire and up it. To ascertain 
 in a rough way, how much air is required per minute to make 
 the fire burn well without smoking, set the door open until the 
 fire is burning properly, then gradually close it until smoke 
 again begins to appear. Then open it a little wider and hold 
 it in such a position as will admit the necessary supply. Now 
 observe the width of the open crevice between the edge of the 
 door, and the rabbet into which it would shut. Suppose this 
 distance to be half an inch in a door eight feet high ; the room 
 would, in such case, require for the entrance of the air an aper- 
 ture equal to 48 square inches, or a hole six inches by eight 
 inches. This however would be more than is usually required. Dr. 
 
SO THE CAUSES AND REMEDIES 
 
 Franklin found that a square opening of six inches to the side, 
 was a good medium size for most chimneys. But now comes the 
 difficulty (at least in English houses, where no air duct is 
 provided by the architect and builder, as in the Polignac fire- 
 place), where to make this opening. If made in the door, it 
 not only interferes with the privacy of the room, but admits 
 of cold draught to the back and feet of those sitting near the 
 fire ; if made in the window, it brings a cataract of cold air 
 down upon the heads of the inmates. 
 
 It has been proposed to cut a crevice in the upper part of 
 the window frame, and to place below this a thin shelf, sloping 
 upwards, in order to direct the air towards the ceiling, where 
 mingling with the heated air of the apartment, it would mitigate 
 its temperature, and bring it down again to feed the fire. The 
 objection to this plan is, that it would cool the room ; but as 
 fresh air admitted from any other source would have a similar 
 cooling effect, it is not easy to propose a better plan. An 
 old fashioned contrivance for kitchens was to place in one of 
 the spaces of the window-frame a circular tin plate, containing 
 a wheel mounted on an axis, the radii or vanes being bent 
 obliquely ; these being acted on by the entering air, forced it 
 round like the vanes of a windmill, and at the same time dis- 
 persed the air to a certain extent, and prevented a distinct 
 draught from being felt. Another method was to take out a 
 pane of glass and substitute a tin frame, giving it two spring- 
 ing angular sides, and being furnished with hinges below, it 
 could be drawn in more or less above, so that the incoming 
 air might be directed upwards, and regulated as to quantity. 
 A contrivance has lately been introduced for ventilating rooms, 
 but when there is a fire in the room, it must serve the purpose 
 of introducing air instead of letting it out. It consists of 
 a number of strips of plate glass, arranged after the fashion 
 of a Venetian blind, occupying the position of one of the 
 panes of glass in the upper window frame. By a little 
 adjusting motion, the strips can be separated more or less 
 apart, to regulate the supply of air, or closed entirely, so as 
 
OP SMOKY CHIMNEYS. 87 
 
 to exclude it. Perforated panes of glass have also been in- 
 troduced as ventilators, but they must also bring air into the 
 room instead of letting it out, when a fire is burning. 
 
 A second cause of smoky chimneys arises from the size of 
 the fire-place ; it may be too wide or too high. Dr. Franklin 
 recommended that the openings in the lower rooms should 
 be about 30 inches square and 18 deep ; and those in the 
 upper rooms only 18 inches square and not quite so deep ; the 
 intermediate openings diminishing in proportion to the height 
 of the funnel. 
 
 But the funnel itself may be too high compared with the 
 size of the fire. The hot air ascending to a certain height 
 may distribute its heat to the air in the upper part of the 
 flue, so that the whole may cool down, and the column within 
 the flue be nearly of the same weight as an equal column on 
 the outside. In such a case, there will be little or no draught 
 to carry off the smoke, and it will, therefore, enter the room. 
 
 But it more frequently happens that the funnel is too short. 
 The remedy in such case is to contract the opening of the 
 chimney, so as to force all the air that enters to pass through 
 or very near the fire. 
 
 In some houses, instead of having a separate chimney for 
 each room or fire-place, the flue is bent or turned from an 
 upper room into the flue of another fire from below. In such 
 a case, the upper chimney is too short, since the length can 
 only be estimated from the place where it enters the flue of 
 the lower room j and this, in its turn, is also shortened in 
 efficient length by the distance between the entrance at the 
 second funnel and the top of the stack ; for all that part being 
 supplied with air from the second funnel, adds no force to the 
 draught ; and if there is no fire in the second chimney, it 
 cools the hot current of the first, and so diminishes the 
 draught. The remedy in this case is to close the opening of 
 that chimney in which there is no fire. 
 
 Chimneys often overpower each other, and so cause them 
 to smoke. If, for example, there are two fire-places in one 
 
88 SMOKY CHIMNEYS. 
 
 large room with fires in each, and the doors and windows 
 dosed ; if the two fires do not burn equally well, either from 
 not being lighted at the same time, or not equally supplied 
 with fuel, or from any other cause, the stronger fire will over- 
 power the weaker, and draw the air down its funnel to supply 
 its own demand. The air descending the funnel of the weaker 
 fire brings the smoke with it, and thus fills the room. Two 
 chimneys in different rooms, which communicate by a door, may 
 also act in this way whenever the door is opened j so, also, in 
 a house where all the doors and windows fit tightly, a strong 
 kitchen chimney on the lowest floor may overpower any other 
 chimney in the house, and draw air and smoke into the rooms 
 as often as a door communicating with the staircase is opened. 
 Dr. Franklin mentions the case of a nobleman's house in 
 Westminster afflicted with this troublesome complaint. It 
 was a new house, and after the owner had paid for it, and 
 discharged all claims, he had to expend .300 more before the 
 smoky chimneys were cured. Of course, the only remedy 
 for this disorder is, to provide each room with the means of 
 furnishing the fire-place with a sufficient supply of air for the 
 combustion of the fuel. When will architects and builders 
 be convinced of the fact, that fire-places, as well as human 
 beings, require constant supplies of fresh air, and that it is 
 their duty to provide every room with air channels, placed so 
 as to feed the fire without annoying the inmates ? 
 
 Another fruitful source of smoky chimneys is, when their 
 tops are commanded by higher buildings, or by a hill, so that 
 the wind blowing over them, falls like water over a dam, 
 sometimes almost passing over the tops of the chimneys, and 
 beating down the smoke. If the funnels cannot be raised, so 
 that their tops may be of the same height or higher than the 
 eminence, the only remedy is to mount one of those ugly 
 contrivances with which the chimney doctors delight to 
 satirise the architect and builder, and which are thus enu- 
 merated by an amusing writer in Chambers's Edinburgh 
 Journal: " The simplest of all consists in the well-known 
 
VARIETIES OP CHIMNEY COWLS. 89 
 
 revolving bonnets or cowls, with wind-arrows on their sum- 
 mits ; which, by the way, were once called Bishops in Scot- 
 land, while a friend assures me, that in the west of England 
 he has heard them styled Presbyterians. The philosophy of 
 this contrivance is sufficiently simple, in whichever direction 
 the wind blows, the mouth of the chimney is averted from it. 
 This principle has its development in a thousand devices- 
 some looking like Dutch ovens come up to see the world, 
 some like half sections of sugar loaves, some like capital H's, 
 and sundry other pleasing objects. The red chimney-pots, 
 too, have contrivances of a similar intention, in the diverging 
 spouts and cavities and twists which some of them delight in. 
 A different species, is the perforated whirling variety, which 
 seem perpetually whizzing round for the mere fun of the 
 thing, since any good they do is extremely apt to escape 
 detection. They are a lively-looking apparatus; but on 
 squally nights, and when the pivot becomes a little rusty, 
 the musical sounds they give forth can scarcely be considered 
 agreeable. Among the more ingenious of smoke-curers, an 
 invention of recent origin, named the Archimedean screw ven- 
 tilator deserves a place. It consists, as its name implies, of 
 wind-vanes attached to the extremity of a revolving screw. 
 When the wind strikes these vanes, it produces a rapid revo- 
 lution of the screw, which is thus supposed to wind up the 
 smoke or vitiated air from below. Perhaps it serves the 
 proposed end ; but whether the positive advantage thus gained 
 is not lost by the obstruction of such apparatus to the free 
 passage of smoke in calm weather, is a point, in my esti- 
 mation, more than questionable. For the relief of such 
 chimneys as only smoke in windy weather, perhaps, this and 
 other forms of external apparatus are best adapted. Another 
 invention of equal merit, is a chimney-cap of metal externally 
 grooved in a series of spiral curves up the pipe, which end 
 in a kind of mouth-piece, from whence the smoke issues. 
 The wind, when impelled against this apparatus, is supposed 
 to take somewhat of the direction of the spiral grooves, and 
 
90 
 
 THE CAUSES AND REMEDIES 
 
 thus to form an upward current to assist the emission of the 
 smoke." One of the most recent of this class of inventions is 
 Day's wind-guard, which consists of an octagonal metallic 
 chimney-cap, having four slits in it, which are protected by 
 projecting pieces or slips of metal. When a current of air 
 strikes in any direction against the cap, it reflects or turns 
 the air in such a manner, as immediately to produce a 
 draught up the pipe. " In casting one's eye down the long 
 streets of the smoky city, in taking a survey of the roofs 
 and their tormented chimneys, the infinity of other contri- 
 vances is so great, that it is scarcely a poetical hyperbole to 
 say our pen starts back from it. Here is patent upon patent, 
 scheme after scheme, each doing its best, no doubt, to obtain 
 the mastery over that simple thing smoke ; and each with a 
 degree of success of a very hopeless amount. There appears 
 to me something intensely ludicrous in these struggles against 
 what seems to be an absurd, but an invincible foe ; the very 
 element of whose success against us lies in our not strangling 
 him in his birth. Many obstacles are in the way, no doubt ; 
 there are obstacles in the way of every good ; but I have little 
 doubt, that had the perverted ingenuity which has mis-spent 
 itself upon the chimney-pots been directed to the fire-place, 
 we might have now had a different tale to tell. The smoke 
 nuisance is laughed at as a minor evil, by a great practical 
 people like ourselves, who heroically make up our minds to 
 put up with it ; but when it is considered as an item in the 
 comfort, cleanliness, and health of a whole nation, it assumes, 
 or should assume, a different position." 
 
 We do not by any means affirm that the above contrivances 
 are always effectual in the cure of smoky chimneys ; for it is 
 easy to imagine cases where chimneys will, or rather must 
 smoke, in spite of the whole host of caps, cowls, and vanes. 
 For example, when a commanding eminence is farther from 
 the wind than the chimney commanded, the wind would, as 
 it were, be dammed up between the house and the eminence, 
 and force its way down the chimneys in whatever position the 
 
OF SMOKY CHIMNEYS. 
 
 91 
 
 turn-cap or other contrivance might be situated. Dr. Frank- 
 lin, mentions a city in which many houses were tormented 
 with smoky chimneys by this operation, for their kitchens 
 being built behind, and connected by a passage with the 
 houses, the tops of the kitchen chimneys were thus lower than 
 the tops of the houses, and thus, when the wind blew against 
 the backs of the houses, the whole side of a street formed a 
 dam, and the obstructed wind was forced down the kitchen 
 chimneys, and passed along the passages into the houses, and 
 so into the street. This was especially the case when the 
 kitchen fires were burning badly. In summer, the annoyance 
 assumed a different form, for the smoke was wafted from the 
 kitchen chimneys into the chambers of the upper rooms. 
 
 Chimneys, which otherwise draw well, will often smoke from 
 the improper situation of a door. Thus when the door and 
 the chimney are on the same side of the room, and the door, 
 being in the corner, is made to open against the wall, as is 
 usually done, to have it more out of the way, it follows that, 
 when the door is partially opened, a current of air rushes in 
 and passes along the wall into and across the opening of the 
 fire-place, and whisks the smoke into the room. This happens 
 more frequently when the door is being shut, for then the force 
 of the current is increased, and persons sitting near the fire 
 feel all the inconvenience both of the draught and the smoke. 
 A remedy may be found by an intervening screen, projecting 
 from the wall and passing round a great part of the fire-place ; 
 or still better, by shifting the hinges of the door, so as to throw 
 the air along the other wall. 
 
 A room with no fire in it is sometimes filled with smoke 
 from the funnel of another room, in which a fire is burning. 
 This arises from changes in density of the air in the cold funnel, 
 from changes in temperature by day and by night, as well as 
 from changes in the direction of the wind. It is found that 
 when the temperature of the outer air and of that in the 
 funnels is nearly equal, the air begins to ascend the funnels as 
 the cool of the evening comes on, and this current will continue 
 
iJZ THE CAUSES AND REMEDIES. 
 
 till nine or ten o'clock next morning ; then, as the heat of the 
 day approaches, it sets downwards and continues to do so till 
 evening ; it then changes again and continues to go upwards 
 during the night. Now when the smoke from the tops of 
 neighbouring funnels passes over the tops of funnels which 
 are drawing downwards, the smoke is also drawn down and 
 descends with the air into the chamber. The remedy proposed 
 by Dr. Franklin, was to contract the opening of the chimney 
 to about two feet between the jambs, and to bring the breast 
 down to about three feet of the hearth. An iron frame is then 
 placed just under the breast, and extending to the back of the 
 chimney, so that a plate of iron may slide horizontally back- 
 wards and forwards in the grooves on each side of the frame ; 
 this plate, when thrust quite in, fills up the whole space, and 
 shuts up the chimney entirely when there is no fire. But 
 when there is a fire, it can be drawn out, so as to leave between 
 its further edge and the back, a space of about two inches, which 
 is sufficient for the smoke to pass ; and so large a part of the 
 funnel being stopped by the rest of the plate, the passage of 
 warm air out of the room up the chimney is in great measure 
 prevented, as is also the cold air from crevices to supply its 
 place. The effect is seen in three ways : 1, When the fire burns 
 briskly in cold weather, the howling or whisking of the wind, 
 as it enters the room through the crevices when the chimney 
 is open, ceases as soon as the plate is slid in to its proper distance. 
 2, Opening the door of the room about half an inch, and hold- 
 ing the hand against the opening near the top of the door, you 
 feel the cold air coming in against your hand, but weakly if the 
 plate be in. Let another person draw it out, so as to let the 
 air of the room go up the chimney with its usual freedom in 
 open chimneys, and you immediately feel the cold air rushing 
 in strongly. 3, If something be set against the door, just 
 sufficient when the plate is in to keep the door nearly shut, by 
 resisting the pressure of the air that would force it open, then, 
 when the plate is drawn out, the door will be forced open by 
 the increased pressure of the outward cold air endeavouring to 
 
OF SMOKY CHIMNEYS. 93 
 
 get in, to supply the place of the warm air that now passes 
 out of the room to go up the chimney. " In our common open 
 chimneys," says the Doctor, "half of the fuel is wasted, and its 
 effect lost; the air it has warmed being immediately drawn off." 
 
 The form of the chimney-pot has also an influence on the 
 free passage of the smoke. Many of those fancy chimney- 
 pots ornamented, singly or clustered together, will cause the 
 chimneys to smoke in strong winds ; the ornaments serving 
 as points of resistance to the wind, after reflecting it down the 
 chimney ; and the clustered arrangement presenting a broad 
 resisting surface, so that the wind, in blowing against them, 
 rises up along the surface, and blows strongly over the mouths 
 of the pots, so that the smoke cannot force its way through the 
 blast. In Venice, the top of the flue is rounded into the true 
 form of a funnel, and this is often found to answer the purpose ; 
 but, at present, we do not know of any remedy except a turn- 
 cap, or one of the many elegant contrivances which give such 
 wonderful variety to the sky line of most of our houses and 
 public buildings. 
 
 Cases of smoky chimneys may arise, which may puzzle the 
 science of the most accomplished smoke doctor. We borrow 
 two such cases from Franklin. " I once lodged," he says, " in a 
 house in London, which, in a little room, had a single chimney 
 and funnel. The opening was very small, yet it did not keep 
 in the smoke, and all attempts to have a fire in this room were 
 fruitless. I could not imagine the reason ; till at length, 
 observing that the chamber over it, which had no fire-place in 
 it, was always filled with smoke when a fire was kindled below, 
 and that the smoke came through the cracks and crevices of 
 the wainscoat. I had the wainscoat taken down, and discovered 
 that the funnel which went up behind it, had a crack many 
 feet in length, and wide enough to admit my arm ; a breach 
 very dangerous with regard to fire, and occasioned, probably, by 
 an apparent irregular settling of one side of the house. The 
 air entering this breach freely, destroyed the drawing force of 
 the funnel. TJie remedy would have been, filling up the breach, 
 
94 CASES OF SMOKY CHIMNEYS- 
 
 or rather rebuilding the funnel j but the landlord rather chose 
 to stop up the chimney." 
 
 The second case occurred at the house of a friend near 
 London. " His best room had a chimney, in which he told 
 me he never could have a fire, for all the smoke came out into 
 the room. I flattered myself I could easily find the cause, and 
 prescribe the cure. I opened the door, and perceived it was 
 not want of air. I made a temporary contraction of the 
 opening of the chimney, and found that it was not its being 
 too large that caused the smoke to issue. I went and looked 
 up at the top of the chimney, its funnel was joined in the 
 same stack with others, some of them shorter, that drew very 
 well, and I saw nothing to prevent its doing the same. In 
 fine, after every other examination I could think of, I was 
 obliged to own the insufficiency of my skill. But my friend, 
 who made no pretension to such kind of knowledge, afterwards 
 discovered the cause himself. He got to the top of the funnel 
 by a ladder, and looking down, found it filled with twigs and 
 straw cemented by earth, and lined with feathers. It seems, 
 the house, after being built, had stood empty some years before 
 he occupied it \ and he concluded that some large birds had 
 taken the advantage of its retired situation to make their nests 
 there. The rubbish, considerable in quantity, being removed, 
 and the funnel cleared, the chimney drew well, and gave satis- 
 faction." 
 
 It has been remarked, that chimneys situated in the north 
 wall of a house, do not draw so well as those in a south wall ; 
 because when cooled by north winds, they are apt to draw 
 downwards. Hence, chimneys enclosed in the body of a house, 
 are more favourably situated than those in exposed walls. 
 Chimneys in stacks often draw better than separate funnels, 
 because those that have constant fires in them warm those in 
 which there are none. 
 
 We have devoted a considerable space to this subject, because 
 we think the reader has a right to expect, in a practical book 
 of this kind, tolerably full information on a subject, in which 
 
DEFECTS OF THE OPEN FIRE-PLACE. 95 
 
 all are interested ; and the above cases seem to include most of 
 the causes of smoky chimneys and their remedies. The open 
 fire-place is so intimately connected with an Englishman's ideas 
 of domestic comfort, that it can never be expected, while coals 
 are plentiful, that a more economical method of warming our 
 rooms will become very common. It is, therefore, the duty of 
 scientific men, to make the open fire-place as comfortable as it 
 certainly is wholesome, and if a better method of supplying air 
 to the fire than the present chance arrangement were adopted ; 
 if caliducts were led round the fire, so as to discharge warm 
 air into distant parts of the room, and even over the house ; if 
 the various parts of the fire-place were of the proper shape 
 and dimensions; there seems to be no good reason against 
 retaining our cherished open fire, and converting it from a 
 troublesome, uncertain, smoky, and expensive companion, into 
 a source of health, pleasure, and economy. 
 
 CHAPTER II. 
 
 ON THE METHODS OF WARMING BUILDINGS BY MEANS OF CLOSE 
 STOVES AND HOT-AIR APPARATUS. 
 
 ONE of the most intelligent advocates* in the cause of the 
 CLOSE-STOVE versus the OPEN FIRE-PLACE, has preferred a very 
 serious bill of indictment against the defendant. It consists 
 of no less than eleven counts, of which the following is a sum- 
 mary. I. Waste of fuel Of the whole heat produced from 
 the fuel used, about seven-eighths ascend the chimney and are 
 wasted. The loss of heat is first, more than half, which is 
 in the smoke as it issues from the burning mass. Secondly, 
 that carried off by the current of the warmed air of the room, 
 
 * Dr. Arnott. " Warming and Ventilation, with Directions for 
 making the Thermometer Stove, d-c." London, 1838. The writer 
 wishes to acknowledge his obligations to this excellent little treatise. 
 
96 DEFECTS OF THE OPEN FIRE-PLACE. 
 
 which is constantly entering the chimney between the fire and 
 the mantel-piece, and mixing with the smoke. This is esti- 
 mated at nearly two-eighths. Thirdly, the soot, or visible 
 part of the smoke, is unburned fuel, and if more than half of 
 the heat produced be in the smoke, and nearly a fourth of it 
 in the warm air from the room which escapes with the smoke, 
 and if about an eighth of the combustible pass away unburned, 
 there is a loss of at least seven-eighths of the whole. Count 
 Rumford estimated the loss at fourteen-fifteenths. These 
 estimates must of course be supposed to refer to the open fire- 
 place with square jambs. II. Unequal heating at different dis- 
 tances from the fire. As the intensity of radiant heat is only 
 one-fourth as great at a double distance, and so on, its effect 
 being inversely as the square of the distance, the walls of the 
 room are scarcely heated, and therefore reflect no heat to 
 persons round the fire. There is usually one circular line 
 around the fire in which persons must sit to be comfortable ; 
 and within this line they are too hot, and beyond it too cold. 
 III. Cold draughts from doors and windows. IV. Cold foot- 
 bath. The fresh entering air, being colder than the general 
 mass already in the room, occupies the bottom of the apart- 
 ment, and forms a dangerous cold air-bath for the feet of the 
 inmates, so that they must keep their feet raised out of it by 
 foot-stools, or wear warmer clothing. We see how anxious 
 cats are to get out of this cold air-bath by occupying the seats 
 of chairs, &c., instead of the carpet. V. Bad ventilation. 
 The heated respired air ascends to the ceiling, and, getting 
 cool, descends, and is breathed over again ; or, if the fire be 
 not sufficiently supplied with air from the door and windows, 
 it will come from other quarters, and bring in foul air from 
 drains, &c. VL Smoke and dust. VII. Loss of time in 
 lighting the fires in the morning, and again during the day if 
 neglected and allowed to go out. VIII. Danger to property. 
 In London alone there are, at an average, 140 fires per month. 
 IX. Danger to the person. Children get burnt, and the 
 dresses of ladies sometimes take fire by a sudden draught 
 
THE DUTCH STOVE. 
 
 97 
 
 from the door, or coining too near the fire. X. Expense of 
 attendance. It is contended that servants have more work 
 to do in houses with open fires, than where stoves are kept. 
 XI. Necessity of sweeping-boys. 
 
 This is certainly a formidable indictment, but after the 
 details given in the last chapter, it is not necessary to enter 
 upon any further defence. There is no doubt that, upon some 
 of the counts, the defendant must be found guilty ; but it will 
 be seen, in the present chapter, that the plaintiff does not 
 come into court with clean hands, for there are many objections 
 to the close stove, from which the open grate is entirely free. 
 These will be stated as we proceed. 
 
 The close stove is used chiefly in those countries where fuel 
 is scarce. One of the simplest forms is the Dutch stove, shewn 
 Fig. 29. in Fig. 29. The fuel rests on the bars 
 
 of a grate, near the bottom, and the air 
 enters below the grate. The fuel is 
 introduced by a door above the grate, 
 which door is closed while the stove is 
 in action, and as this is the only opening 
 in the stove above the fuel, no air can 
 reach the chimney, except that which 
 has passed through the fire, thus saving 
 the waste of warm air, which, in open 
 fires, passes between the fire and the 
 mantel-piece. The heating effect of this stove is due to the 
 whole surface of the stove, and its flue receiving the direct 
 heat of combustion, as well as much of the heat of the pro- 
 ducts of combustion, as they escape into the chimney, and, if 
 the flue be made sufficiently long, so as to expose a large sur- 
 face in the room, nearly the whole of the heat may be applied 
 to use, without draughts, or smoke, or dust. These are the 
 good qualities of the Dutch stove j now for its bad ones. The 
 heated iron surface acts upon the air in contact with it, so as 
 to impair its purity and fitness for respiration. " The air," 
 says Dr. Arnott, " acquires a burnt and often sulphurous 
 
98 OBJECTIONS TO THE DUTCH STOVE. 
 
 smell, in part, no doubt, because dust, which it often carries, 
 is burned, and, in part, because there is a peculiar action of the 
 iron upon the air. It becomes very dry, too, like that of an 
 African simoom, shrivelling everything which it touches ; and 
 it acquires probably some new electrical properties. These 
 changes combined make it so offensive, that Englishmen, un- 
 accustomed to it, cannot bear it. In this country, many forms 
 have been proposed, some of them gracefully designed, with 
 transparent talc doors, and other attractions ; and they have 
 been tried in rooms, public offices, passages, halls, &c., but have 
 been afterwards very generally abandoned. Persons breathing 
 the air heated by them, are often affected by headaches, giddi- 
 ness, stupor, loss of appetite, ophthalmia, &c. A north-east 
 wind, which distresses many people, bringing asthmas, croups, 
 &c. } and which withers vegetation, is peculiar chiefly in being 
 dry." This stove is much used by laundresses and others for 
 drying, and in this application of it, the doctor admits, it is 
 good and economical. The ornamental varieties of it are also 
 furnished with vases and other receptacles for water, which, by 
 its evaporation, greatly mitigates the evils complained of ; but 
 it must be admitted, that the list of objections brought against 
 the Dutch stove forms as formidable a bill of indictment as that 
 preferred against the open fire. Another objection not no- 
 ticed in the above quotation, arises from the overheating of 
 the flue. It has often been known to get red-hot, and has 
 thus led to serious conflagrations. 
 
 The American stove is a square close iron box, with a vessel 
 of water upon it, to give moisture to the air. It has a plate 
 Fig - 30 - projecting under the door, D (Fig. 
 
 30); the wood fuel is burned 
 within at A, and the flame passes 
 along by B, to the chimney, c, 
 around an inner box, which is the 
 cooking oven of the family, open- 
 ing by a door in the side of the 
 stove. The fuel is introduced by 
 
 I 
 
STOVES IN THE NORTH OF EUROPE. 99 
 
 a large door at D, in which there is a smaller door, which, as 
 well as the larger, is usually kept shut, because a sufficient 
 supply of air enters by the joinings around; but in cold 
 weather, the small door is opened to increase the combustion. 
 The stove has iron legs, about a foot in length. 
 
 In Russia, Prussia, and the North of Europe generally, the 
 stove is a very important article of domestic furniture, in which 
 the largest possible amount of heating effect is obtained from 
 the smallest possible quantity of fuel. In the construction of 
 these stoves, the following points are kept in view : To main- 
 tain in the fire-place the high temperature necessary for the 
 perfect combustion of the fuel, by surrounding it with such 
 substances as are bad conductors of heat, such as fire-stone or 
 bricks ; to have the means of regulating the quantity of air 
 admitted to the fuel, by valves in the doors which enclose the 
 ash-pit and fire-chamber, and by accurate fitting of the doors 
 and valves themselves. Thirdly, to bring all the gaseous pro- 
 ducts of combustion, as they escape from the fuel, into contact 
 with the largest possible area of slowly conducting surface, so 
 as to maintain it at an equal temperature j and, lastly, to make 
 the smoke enter the chimney with the smallest velocity, or 
 lowest temperature, that is practically consistent with the first 
 condition. In no case, should this temperature exceed 150, 
 nor should the metallic surface ever be raised higher than 
 100, nor the stream of air issuing from it exceed 70. In 
 every case, the combustion is regulated by limiting the supply 
 of air, and if the heating surface be small, the fire is reduced 
 so as to produce no more heat than can be carried off by the 
 radiation and conduction of such heating surface. 
 
 The method in which these conditions are complied with, 
 will be understood by referring to Fig. 31, which represents a 
 general form of stove. It may be modified according to 
 circumstances of utility or taste, but the principle is the 
 same in all. M I K L is a quadrangular box of any size, in 
 the directions MILK; but the inside width, from front to 
 
 F 2 
 
100 
 
 STOVES IN THE 
 
 back, is generally pretty constant ; it 
 is never less than 10 inches, and 
 seldom extending to 20 inches. The 
 whole included space is divided by 
 a number of partitions. The lowest 
 chamber, B, serves for the fuel, 
 which is placed on the bottom of the 
 stove without any grate. The fire- 
 place has a door, o, turning on 
 hinges, and in this door is a small 
 wicket, P. The roof of the fire-place 
 extends to within a very few inches of the further end, having a 
 narrow passage, B, for the flame. The next partition, d, is 
 about eight inches higher, and reaches almost to the other end, 
 leaving a narrow passage for the flame at D. The partitions 
 efg care repeated above at the distance of eight inches, leaving 
 passages E F G c at the ends alternately disposed, the last com- 
 municating with the vent in the H flue. This communication 
 is regulated by an iron plate, or damper, N L, which can be 
 slid across it by moving a rod, which passes out through the 
 side. If the fuel be wood, as is generally the case, and the 
 vent opens into the room, this passage is closed by a sort of 
 pan, or bowl of earthenware, which is inverted over it, with its 
 brim buried in sand, contained in a groove formed all round 
 the hole. The whole stove is set on low pillars, so that its 
 bottom may be a few inches from the floor of the room. It 
 is usually placed in a corner of the apartment, which is so 
 disposed that the chimneys can be joined in stacks, as with us. 
 In lighting the stove, straw or wood shavings are first burnt 
 on the hearth at its farther end, in order to warm the air in 
 the stove and determine a current. The fuel is then laid on 
 the hearth close by the door, and piled up and kindled, and 
 the current, being already directed to the vent, there is no 
 danger of smoke getting out into the room. The door, o, is 
 then closed and the wicket, p, opened, and the air supplied by 
 
NOETH OF EUROPE. 101 
 
 this means, being directed to the middle or bottom of the 
 fuel, it is quickly kindled and is soon burning well. 
 
 Now it will be seen, by this construction, that the flame, and 
 heated products of combustion are retained as long as possible 
 within the body of the stove, and their heat diffused over 
 a very extended surface, which is still further increased by 
 making the stove narrower from front to back in its upper 
 part. A certain breadth is necessary below, that there may be 
 room for the bulky wood fuel ; but if this breadth were 
 preserved all the way up, much heat would be lost, because 
 the heat, communicated to the partitions of the stove, acts 
 with little or no useful effect, so that, by diminishing their 
 breadth, the proportion of heating surface is increased. The 
 whole body of the stove may, as Professor Robison remarks, be 
 considered as a long pipe folded up, and its effect would be the 
 greatest possible, if it really were so, that is, if each partition 
 were split into two, and a free passage allowed between them 
 for the air of the room. 
 
 In order that the heated surface may be as extensive as 
 possible, the stove is not built into the wall, nor in contact 
 with it, or with the floor. By being thus detached, both the 
 back and bottom of the stove are sources of heat to the air of 
 the room, and the bottom, which is the hottest part, contri- 
 butes at least half the heating effect. Sometimes, however, the 
 stove forms a part of the wall between two rooms, and serves 
 to heat both. It is also common to have the door of the 
 fire in the passage on the outside of the room, so that 
 an attendant can manage it without incommoding the 
 occupants. 
 
 The author of A Residence on the Shores of the Baltic, 
 1841, refers to these stoves in the following terms : "Within 
 these great houses, not a breath of cold is experienced. The 
 rooms are heated by stoves, frequently ornamental rather than 
 otherwise ; being built in tower-like shapes, story over story, 
 of pure white porcelain, in various graceful architectural 
 mouldings; sometimes surmounted with classic figures of great 
 
102 OBJECTIONS TO THE USE OF 
 
 beauty, and opening with brass doors, kept as bright as if 
 they were of gold. In houses of less display, these stoves are 
 merely a projection in the wall, coloured and corniced in the 
 same style as the apartment. In adjoining rooms they are 
 generally placed back to back, so that the same fire suffices 
 for both. These are heated but once in the twenty-four hours 
 by an old caliban, whose business during the winter it is to do 
 little else. Each stove will hold a heavy armful of billet, 
 which blazes, snaps, and cracks most merrily ; and when the 
 ashes have been carefully turned and raked with what is 
 termed an of en gabel, or stove fork, so that no unburnt morsel 
 remains, the chimney aperture is closed over the glowing 
 embers, the brass doors firmly shut, and in about six hours 
 after this, the stove is at the hottest indeed, it never cools." 
 
 The useful eifect of this stove depends very much on re- 
 taining in the room the air already heated by it. A small 
 open fire in the same room will actually diminish the heating 
 effect of the stove, and even draw the warm air from adjoining 
 apartments. In the houses of English merchants at St. 
 Petersburg, open fires are sometimes introduced into rooms 
 with stoves ; and the consequence is, that it is found necessary 
 to light the stoves twice a day, and yet the houses are cooler 
 than those of the Russians, who light them only once. To 
 our notions, however, a cool in-door atmosphere is preferable 
 to a nauseous stagnant one, such as the Russians and Germans 
 are accustomed to breathe throughout the winter ; and even 
 in summer, they are very averse to an open window. The tem- 
 perature of the winter apartments is kept nearly always at 
 65, and as every part of the room is equally warm, the in- 
 mates have no occasion to crowd round the stove as we do 
 round the fire. " But I can testify," says Dr. Buxton, " that 
 in German rooms there is a closeness of feeling to a person 
 accustomed to free air, which is unpleasant, if not unwhole- 
 some no change of air, the windows closed as tight as can 
 be, and the door fits as exactly as the carpenter can make it. 
 The stove is air-tight with regard to the room, and there is 
 
RUSSIAN AND GERMAN STOVES. 103 
 
 nothing to occasion a current like an English open fire. The 
 apartments of the sick almost invariably smell disagreeably. 
 I do not, however, recollect seeing a single ventilator in 
 Germany ; but I have repeatedly seen double windows." As 
 ventilation can only be procured at the expense of heat, the 
 people prefer retaining the foul air to expending an extra 
 portion of fuel. In the houses of the poorer classes in Russia, 
 where the windows are single, and a number of persons occupy 
 a small stove-heated room, a thick icy crust forms on the 
 inside of the windows during frosty weather, arising from the 
 condensation of the breath, perspiration, and the aqueous 
 fumes of candles, and of the stove, &c. When a thaw comes 
 on, this icy crust is converted into water, and a deleterious 
 principle is disengaged, which produces effects similar to those 
 arising, from the fumes of charcoal. Persons so affected are 
 immediately carried into the open air, and placed on the snow 
 with very little clothing j the temples and the region of the 
 stomach are well rubbed with snow, and cold water is poured 
 down their throats, and the friction is continued until the livid 
 hue of the skin disappears, and the natural colour is restored. 
 The Chinese are wiser in this respect than the Russians, for, 
 although their rooms may in winter be as hot and as crowded, 
 they have two openings at the top of each window, which are 
 never allowed to be closed, and through these ventilation is 
 carried on. 
 
 The stove last described belongs rather to that variety 
 called the Sivedish stove, than to the Russian or German. In 
 the Russian or German stove, the smoke, after rising from the 
 fuel, recedes into the flue, and becomes cooled by contact with 
 the walls of the circulating chambers, and the heat is by this 
 means retained in the apartment which would otherwise have 
 escaped combined with the vapour. In the Swedish stove, 
 the circumvolutions of the smoke are exposed to a vivid heat, 
 so that every particle of soot undergoes a second combustion 
 in the circulating channels. Some of the Swedish stoves have 
 from four to nine channels for the circulation of the smoke ; 
 
104 STOVES WITH ASCENDING AND 
 
 some are contrived to receive one or more boilers, and others 
 to act as ovens ; and they all greatly economise the fuel, for, 
 according to Morveau, the quantity of wood which is con- 
 sumed in twenty-three days in an open fire, with less effect, will 
 last sixty-three days in a stove. 
 
 In erecting the ponderous German stoves, it is necessary to 
 arrange the various pieces of clay, or porcelain, so that no part 
 should crack or give way, and thus admit the smoke or car- 
 bonic acid vapour into the room. When the parts are put 
 together with cement, or held by iron cramps, a leakage com- 
 monly occurs at the joinings, where the different pieces of 
 clay are differently heated, and, perhaps, were of a different 
 baking when made ; hence, by expanding unequally and work- 
 ing on each other, one of them must give way. But instead 
 of making the joints close and using any cement, the best 
 method is to make each upper piece stand in a groove formed 
 in the piece below it, and then to sprinkle a little powdered 
 chalk or clay over it, which will effectually prevent the passage 
 of any air, and, at the same time, allow space for any expansion 
 or contraction at the joint. 
 
 Some valuable experiments by Mr. Bull are quoted by Mr. 
 Bernan, to shew the effect of ascending and descending flues 
 in the Russian and Swedish stoves, and of elbows or bends in 
 the flue of the common Dutch stove. From these experi- 
 ments, it appears that the same length of pipe is much more 
 efficacious in imparting heat to a room when it has elbows 
 than when it is straight ; that a descending current may be 
 somewhat more efficacious than an ascending one, but is about 
 equal with a horizontal one; a horizontal pipe, with the 
 same number of elbows, is more efficacious in imparting heat, 
 than when placed vertically for an ascending and descend- 
 ing current. The cause of the increased effect is supposed 
 to arise from the shape of the pipe forcing the heated air 
 to make abrupt turns ; in doing which, it impinges against 
 the elbows with sufficient force to invert its internal arrange- 
 ment, by which a new stratum of hot air from the interior 
 
DESCENDING CURRENTS. 
 
 105 
 
 of the current is brought more frequently in contact with the 
 sides of the pipe, and particularly with the lower half of the 
 horizontal pipe, which, from various causes, gives out very 
 little heat to the room, without the aid of elbow joints. But 
 the advantage gained by increasing the length of pipe and 
 number of joints, has a limit very far short of that which is 
 found to be necessary to impart all, or the greatest part, of 
 the heat generated to the air of the room. Only five parts of 
 heat in 100 were lost by using 13^ feet of pipe, consisting of 
 nine elbow joints ; whereas, eight additional elbow joints, 
 and 16 J feet additional of straight pipe, in all 28^ feet of 
 pipe, were required to save these five parts, and prevent their 
 flowing into the chimney. By diminishing the diameter of 
 the pipe, the heating effect is increased, partly from the retard- 
 ation of the current, and partly from the small pipe exposing a 
 greater surface to the air with the same quantity of smoke 
 than a pipe of larger diameter. 
 
 An excellent stove with a descending current was con- 
 structed by Dr. Franklin, for his own use. Fig. 32 represents 
 a vertical section, in which x is an open- 
 ing in the cover, furnished with a hinge ; 
 a is a fire-chamber, in which the grating 
 is fixed; b, a space containing a second 
 grating; c, the ash-pit, with a drawer to 
 receive the ashes; d e, horizontal flues at 
 each side of the ash-box, communicating 
 with vertical flues which lead into the 
 chimney. The vase and flues are con- 
 tained in a niche formed by closing up 
 the fire-place, and there is no communL 
 cation between the room and the flue, except through the 
 opening x in the lid. The fire is first lighted between 8 A.M. 
 and 8 P.M., when there is usually a draught up the chimney, 
 as already explained (page 91) ; but the direction of the 
 draught had better be ascertained by holding a flame over the 
 air-hole at the top of the vase. If the flame be drawn strongly 
 
 F 5 
 
 Fig. 32. 
 
106 STOVES WITH 
 
 down, the fire may be lighted by first putting in a little char- 
 coal on the grate at a, ; then lay some small sticks on the 
 charcoal and some paper on the sticks ; set light to the paper 
 and shut down the lid; the air will pass down through the air- 
 hole, and blowing the flame of the paper through the sticks, 
 kindle them, and they, in their turn, will kindle the charcoal. 
 The flame and hot vapour descending through the grating at 
 a, passes into the chamber b, and through the second grating 
 in its bottom into the ash-pit, c. The hot current will then 
 be divided one portion turning to the left, and passing into 
 the horizontal channels d, e, and entering the vertical flue, will 
 be conducted into the chimney ; the other portion will make 
 a similar circuit on the left in the channels d c, and entering 
 another flue, will in like manner pass into the chimney. The 
 surfaces of the vase and air-box, and the part of the horizontal 
 channels exposed to the room, are heated by these circumvo- 
 lutions of the vapour, and the air warmed by contact with 
 them, spreads into the room. The larger pieces of coal that 
 fall through the grating on the vase, are caught by the second 
 grating, 6, and the ashes fall through it into the ash-pit box, c. 
 The success of this excellent contrivance depends of course 
 upon maintaining an upward steady draught in the chimney flue, 
 so that the ash-pit drawer and a door in the chamber 6, to 
 withdraw the cinders, must be made air-tight. In order to 
 determine an upward current on lighting the fire, a small door 
 may be made in the side of the flue, and a piece of lighted 
 paper inserted. 
 
 Mr. Beaumont's stove also acts by a downward current. 
 It is represented in section, in Fig. 33. The foundation, a, is 
 of bricks, two courses high, and 25 inches square, with a vacant 
 space six and a half inches wide, for the ash-hole, b. Upon this 
 foundation are laid two plates of cast iron, c } each 9 inches 
 wide, 25 inches long, and an inch thick. The plate which covers 
 the ash-pit draws out, and in doing so, turns the ashes into the 
 ash-pit. On these iron plates is erected a drum with an aper- 
 ture, Xj for the smoke flue. This aperture, when lined with fire 
 
DESCENDING DRAUGHTS. 
 
 107 
 
 Fig. 33. 
 
 bricks, is six inches wide, and four and a half inches high. The 
 drum is also lined with fire-bricks, set on edge, and is covered 
 
 with a circular plate of cast iron, 
 8 n, with a downward lip round the 
 edge, to receive the upper edge 
 of the drum. In the middle of 
 the cover, n, is a hole, seven 
 inches in diameter, for the admis- 
 sion of fuel, and this ig covered 
 with a lid, moving on a pivot to 
 regulate the admission of the air. 
 An opening of an inch is usually 
 sufficient for that purpose. A short 
 rim projects from the lid, whereby it is converted into a shallow 
 vessel for holding water, the evaporation of which keeps the 
 air sufficiently moist. The fire is lighted by first throwing in 
 a few coals, then some sticks and paper, and, lastly, some cinders 
 or coke, with a little coal immediately over the wood, taking 
 care to make the fuel slope away from the smoke flue. The 
 aperture at the top is then nearly closed, and the fire is lighted. 
 The smoke first tends to rise towards the aperture, but the 
 heat soon determines a downward current, which sets into the 
 smoke aperture, and carrying with it the gaseous products of 
 combustion into the flue, /, the fire soon begins to burn brightly. 
 At night the aperture is closed, and the fire goes out. All the 
 fuel is consumed, the downward draught producing complete 
 combustion ; there is no soot, and nothing of the fuel remains 
 but a red ash. The management of this stove is quite easy; 
 all that is required being to push in the slide, over the ash-pit 
 before the fire is lighted, to let the fire burn brightly before 
 much fuel is put on, and to keep the smoke vent, x, from being 
 choked up, by overloading it with fuel. 
 
 Mr. Beaumont says, that although this stove thoroughly 
 warmed the air of the office, yet the clerks constantly com- 
 plained of cold feet. To remedy this, a flue was formed under 
 the paved floor, the paving-stones forming the roof of it. The 
 
108 IMPROVEMENT ON 
 
 flue, which was a foot square, entered one side of the office, 
 continued along that side, across the top, and down the other 
 side, where it entered an upright flue in the party wall. The 
 pavement thus heated after the Chinese fashion (page 55), 
 made the office very comfortable. With a mere handful of fire, 
 the warmth was so considerable, that the difficulty was to keep it 
 low enough, without putting out the fire. An office and prin- 
 cipal staircase were thus kept warm at an annual expense of 
 30s., or about 3d a day for the cold season, whereas a similar 
 degree of heat from another apparatus cost .18 a year. 
 " Persons coming in from the open air have complained of our 
 keeping large fires, and when they have been shown that the 
 fire was a small one, burning without fierceness, and which 
 might be contained in the crown of a hat, they have denied 
 their belief to the fact ; and insisted that the warmth which 
 they felt must have been procured from some other source. 
 It really does appear like magic, but the case proves the fact 
 of one part only of the heat from the previous apparatus going 
 to the place to be heated, and that eleven parts went up the 
 chimney and was wasted at the house top." 
 
 The stove shewn in section, in Fig. 34, is an improvement 
 on the Dutch stove, already noticed (page 97). The fire- 
 chamber, a, eight inches on each side, is enclosed by four fire- 
 tiles, c c, one inch thick, placed in a cast iron case, three eighths 
 of an inch thick, with a ledge to support the grate. This 
 ledge projects three and a half inches downwards into the 
 ash-pit, and terminates in four short standards, or feet, placed 
 on the sole of the stove. A space, #, of four and a half inches 
 is left between this iron casing, and the inner casing of the 
 stove. Five inches above the upper edge of the tiles of the 
 fire-box, a fire-tile, e, one and a half inch thick, and 15^ inches 
 square, is fixed on brackets, so as to leave a space, r, about one 
 and a quarter inch all round, between it and the inner surface 
 of the casing for the hot vapour from the fuel to rise upwards. 
 A plate of iron, or a tile, n, is fixed about eight inches above 
 the tile, e } leaving also a space, r, about one and a quarter inch 
 
THE DUTCH STOVE, 
 
 109 
 
 between its edge and the casing. The roof of the stove, 
 about eight inches above the plate, terminates in the smoke- 
 pipe, d ; the fire-door and its valve are shown at b, and the 
 
 ash-pit door and air-valve at s, 
 the upper edge of this valve being 
 half an inch above the under edge 
 of the iron casing of the smoke- 
 chamber. The stove is enclosed 
 in a plate-iron casing, so as to 
 leave a space, o, of one and a 
 half inch round it. This casing 
 is open at the bottom, m m, and 
 at the top, p p, and has two fillets 
 projecting about half an inch from 
 its surface ; no valve of any 
 kind is attached to this outward 
 casing, and the air circulates 
 freely through the space, o, that 
 it encloses. All the parts are 
 accurately fitted, and no air 
 enters the stove, except through the valves at s and 6. In the 
 specimen described by Mr. Bernan, " the heating surface was 
 20^ square feet, and the depth of coke in the fire-chamber 
 was generally about five inches ; and this was found sufficient 
 for a room containing nearly 5,600 cubic feet of space. When 
 there is fire, the hot vapour from the fuel being prevented 
 from rising in a stream upwards by the tile, e, spreads along its 
 under surface, and ascends all round the edge of the tile, 
 through the narrow space, r, which brings the smoke into 
 contact with a large surface of the iron casing, and this con- 
 tact is prolonged until it reaches the roof, by flowing through 
 the narrow space between the upper tile and the casing ; the 
 whole surface of the stove thus kept in contact with the smoke, 
 is equally heated, and the air which rises freely in the space, o, 
 being brought rapidly in contact with this hot surface, is 
 genially warmed and emitted at p into the room." 
 
110 THE STOVE -GRATE, OR CHAPELLE. 
 
 A combination of the stove and the grate, combining the 
 heating effect of the stove with the cheerful appearance and 
 ventilating properties of the open fire, is known under the 
 name of the stove-grate, or Chapelle ; the latter name being 
 derived from its resemblance to the chapels or oratories of the 
 great churches. Professor Robison describes it as the most 
 perfect method of warming an apartment. Its construction 
 is as follows : In the great chimney-piece is set a smaller one, 
 of a size no larger than is sufficient for holding the fuel. The 
 sides and back are of cast iron, and are kept at a small distance 
 from the sides and back of the main chimney-piece, and con- 
 tinued down to the hearth, so that the ash-pit is also separate. 
 The pipe or chimney of the stove-grate is carried up behind 
 the ornaments of the mantel-piece, until it rises above the man- 
 tel-piece of the main chimney-piece, and is fitted with a regis- 
 ter, or damper plate, turning round a transverse axis. The 
 best form of this register is that of an ordinary fire-place, with its 
 axis or joint close at the front, so that when open or turned up, 
 the burnt air and smoke, striking it obliquely, are directed 
 with certainty into the vent without any risk of reverberating 
 and coming out into the room. All the rest of the vent is shut 
 up by iron plates or brick-work out of sight. 
 
 The fuel being in immediate contact with the back and sides 
 of the grate, raises them to a great heat, and they heat the 
 air contiguous to them. This heated air cannot get up the 
 vent, because the passage above these spaces are shut up. It 
 therefore comes out into the room ; some of it goes into the 
 real fire-place, and is carried up the vent, and the rest rises 
 to the ceiling, and is diffused over the room. The heating 
 effect of this stove-grate is remarkable. Less than a quarter 
 of the fuel consumed in an ordinary fire-place is sufficient, and 
 this, with the same cheerful blazing hearth, and the salutary 
 renewal of the air. Indeed, it often requires attention to 
 keep the room cool. The heat communicated to those parts 
 of the apparatus, which are in contact with the fuel, is need- 
 lessly great, so that it has been found an improvement to line 
 
Ill 
 
 this part with thick plates of cast iron, or with tiles of fire- 
 clay. These being bad conductors, moderate the heat commu- 
 nicated to the air. If the heat be still found too great, 
 it may be brought under perfect management, by opening pas- 
 sages in the vent for the spaces on each side, so that the air 
 heated by the sides of the stove-grate may ascend directly 
 into the flue, instead of escaping into the room. These pas- 
 sages may be closed by valves, or trap-doors, moved by rods 
 concealed behind the ornaments of the fire-place. 
 
 The stove-grate is under complete control as to tempera- 
 ture. A cheerful fire may be insured within five minutes, 
 simply, by hanging a plate of iron in front so as to reach 
 down as low as the grate ; and when the fire is by its means 
 blown up, the plate may be taken down and sent out of the 
 room, or set up behind the grate out of sight. If, on the 
 other hand, the room be found inconveniently warm, the tem- 
 perature may be cooled down within a quarter of an hour, by 
 opening the side passages to any extent for the escape of the 
 hot air. In this arrangement the ash-pit is enclosed, because 
 the light ashes not finding a ready passage up the chimney, 
 are apt to escape into the room with the heated air. 
 
 Few contrivances for warming apartments have excited 
 more attention and discussion of late years, than Dr. Arnott's 
 stove. The principle of this invention consists, in allowing 
 the fuel to burn very slowly, the admission of air for com- 
 bustion being regulated by a peculiar contrivance. There are 
 various forms and modifications of this stove, but the principle 
 is the same in all. The stove consists of a square or cylin- 
 drical box of iron, lined with fire clay, with a grating near 
 the bottom for the fuel, or the fuel may be contained in a 
 small fire-box within the stove. Sometimes the fuel is burned 
 within a hollow cylinder of fire-clay, and then the stove is not 
 lined with that material. There is an ash-pit below for the 
 ashes, and the products of combustion are carried off by a 
 vent. The chief feature of this stove is, the contrivance by 
 which the air is admitted to the fuel. When the stove -door 
 or ash-pit door is open, the combustion is vivid ; but when 
 
112 
 
 THE ARNOTT STOVE. 
 
 _UL 
 
 these are perfectly tight, as they ought to be, then the air is 
 admitted by a regulator. 
 
 The form first tried is shewn in Fig. 35, in which abed 
 Fi s- 35. represent a box of sheet iron 
 
 divided by the partition, g h, into 
 | two chambers, communicating 
 freely at the top and bottom ; e 
 is the fire-box formed of iron, 
 lined with fire-brick, and resting 
 on a close ash-pit with a door at 
 b, near which is a valved opening, 
 by which air enters to feed the 
 fire when the door is shut ; i is 
 the door of the stove by which 
 fuel is introduced ; c is the chim- 
 ney flue. When the ash-pit 
 door and the stove-door are shut, the quantity of air admitted 
 by the valved opening in the ash-pit is only just sufficient to 
 support combustion, and only a small corresponding quantity 
 of air can pass away by the chimney. The whole box then 
 soon becomes filled with hot air, or smoke from the fire circu- 
 lating in it, and rendering it every where of as uniform tem- 
 perature, as if it were full of hot water. This circulation takes 
 place, because the air in the front chamber around the fire-box, 
 and which receives as a mixture the red-hot air issuing from 
 the fire, is hotter, and, therefore, specifically lighter than the 
 air in the posterior chamber which receives no direct heat, but 
 is always losing heat from its sides and back ; and thus, as 
 long as the fire is burning, there must be circulation. The 
 whole mass of air is, in fact, seen to revolve, as marked by the 
 arrows, with great rapidity. The quantity of new air rising 
 from within the fuel, and the like quantity escaping by the 
 flue, c, are very small compared by the revolving mass. The me- 
 thods of regulating the supply of air will be noticed presently. 
 
 With this stove, Dr. Arnott, during the severe winter of 
 1836-7, was able to maintain in his library a uniform tem- 
 perature of from 60 to 63. The quantity of coal used 
 
ARNOTTS REGULATING VALVES. 
 
 113 
 
 (Welsh stone coal) was, for several of the colder months, six 
 
 pounds a day less than a pennyworth a smaller expense than 
 
 that of the wood used in lighting an ordinary fire. The 
 
 grate or fire-box, fully charged, 
 held a supply for twenty-six 
 hours. 
 
 Another common form of this 
 stove is shewn in Fig. 36 ; 
 A B c D, is the outer casing ; B, 
 the fire-box, over which is a dome, 
 Ic, with a funnel, p, to carry off the 
 products of combustion ; h, is the 
 stove door; and g the regulator 
 by which air is admitted. Vari- 
 ous forms of regulators are de- 
 scribed, but perhaps the best is 
 
 shewn in Fig. 37. ABcis a glass tube 
 
 shut at A, containing air from A to B, and 
 
 filled with mercury from B to c ; on the 
 
 mercury at c is a float from which proceeds 
 
 Fig. 37. 
 
 an upright rod, D, kept steady by passing 
 through a support at H. From this up- 
 right wire descends another, F G H, termi- 
 nated by the plate valve, F ; E is the air- 
 tube of the stove. When the heat within 
 is great, the air in the shut limb of the 
 regulator at A is expanded, and forces up 
 the mercury at c, raising the rods and 
 plate valve, F, and thus bringing it near to 
 or in contact with the mouth of the tube, 
 by which more or less air is admitted to 
 
114 
 
 OBJECTIONS TO THE ARNOTT STOVE. 
 
 Fig. 38. 
 
 the stove, according to the heat within. If the combustion is 
 proceeding too slowly, then the air in the tube A is not much 
 expanded, consequently, air is allowed to enter the stove more 
 freely ; but when owing to this the combustion becomes lively, 
 and the temperature too high, then by the elevation of the 
 plate valve, less air enters, and the temperature is moderated. 
 A still more simple form of regulator is shewn in Fig. 38, 
 
 a b c is a bent tube shut at 
 a, where it contains air, and 
 open at c, where it is cup- 
 shaped. The bent part at 
 b is occupied by mercury ; 
 from c proceeds a bent tube 
 to supply air to the stove. 
 When the internal heat is 
 great, the air in a is ex- 
 panded and forces the mer- 
 cury up in c, and thus, 
 bringing it in contact with 
 the mouth, prevents the free entrance of air to the stove. 
 
 This stove is liable to the objection already stated, viz., that 
 the air of the room, though sufficiently heated, is nevertheless 
 stagnant. A pound of coal requires about 150 cubic feet of 
 air for combustion ; but as a portion of the air escapes without 
 being chemically acted on, 200 cubic feet may be allowed. 
 Now if a room warmed by Arnott's stove, be fifteen feet long, 
 twelve feet wide, and eleven feet high, its cubic contents are 
 1,980 feet ; and if six pounds of coal per day be burnt, each 
 pound requiring about 200 cubic feet, only 1,200 cubic feet 
 will be used for the combustion. This quantity must pass 
 through the stove, and be carried off by the vent, so that in 
 the course of twenty-four hours, the atmosphere of the apart- 
 ment is not once completely changed or renewed by the action 
 of the fire. Hence it is that the apartment is so easily warmed, 
 and hence also its unpleasant effect. 
 
 Another serious objection to this stove, arises from that 
 
JOYCE'S CHARCOAL STOVE. 115 
 
 which is generally considered as its chief merit ; namely, the 
 slow combustion of the fuel, whereby carbonic oxide is gene- 
 rated, and from the small draught of the chimney, is liable to 
 escape into the room. This gas, is poisonous, and its escape 
 has been ascertained by Dr. Ure, by attaching to the ash-pit 
 of one of these stoves a glass vessel containing a solution 
 of subacetate of lead, which being speedily acted on by 
 the carbonic oxide, was formed into the insoluble carbonate 
 of lead. It is also stated, that carburetted hydrogen is some- 
 times formed in these stoves, which, by mingling with the 
 air, has formed an explosive mixture, and thus led to cala- 
 mitous fires. 
 
 Joyce's stove for burning charcoal is liable to all the objec- 
 tions arising from the use of this fuel in an apartment. The 
 charcoal is prepared for this stove by reburning common 
 charcoal in a close oven, and quenching it while hot with an 
 alkaline solution ; this deprives it of its usual pungent smell in 
 burning, but renders it all the more dangerous, since the car- 
 bonic acid may slowly accumulate in an apartment, a bed- 
 chamber, for example, and produce fatal consequences. The 
 stove consists of a thin metal case, in the form of a small urn 
 or vase. A small pipe, two or three inches long, rises through 
 the bottom into the body of the stove, and terminates about 
 the centre in a conical funnel closed at the top, and pierced 
 full of holes. At the top of the stove is a valve, for the pur- 
 pose of regulating the supply of air through the lower pipe, to 
 maintain the combustion. A small portion of ignited char- 
 coal is placed in the stove, and the remaining space filled up 
 with charcoal not ignited ; and as the supply of air is very 
 limited, it will continue to give out heat for many hours. 
 The whole of the charcoal is converted into carbonic acid, 
 which escapes from the valve at the top in proportion to the 
 quantity of air which enters at the bottom. This stove has 
 nothing to recommend it j for the charcoal fuel is not only 
 dangerous, but expensive. From its small size and great calo- 
 rific power, this stove excited considerable attention at the 
 
116 
 
 STOVES WITH A COCKLE. 
 
 time of its introduction ; and from the statements made re- 
 specting it, the public was led to expect that some new law 
 of combustion had been discovered, or that the old law had 
 been suspended in its favour, for it was gravely affirmed, that 
 the whole of the products of combustion were absorbed or 
 otherwise prevented from escaping from the stove, in conse- 
 quence of the peculiar mode of preparing the fuel. 
 
 We come now to notice that variety of stove in which the 
 cockle is introduced. This contrivance is an invention of Mr. 
 Strutt, of Derby, and consists in making the fire-chamber of 
 a cylindrical form, with a flat or dome-shaped head, and a pipe 
 leading from the upper part, to carry off the smoke into the 
 chimney. This iron fire-room, called the cockle from its shape, 
 was then placed on a bed of masonry or brickwork, with a 
 
 grating and ash-pit beneath, 
 as shewn in Fig. 39. At a 
 certain distance from the 
 cockle, a, is a mass of brick- 
 work, b b, concentric with the 
 cockle and its dome top, in 
 order to allow a current of 
 air from the passages below, 
 or from the external atmos- 
 phere, to come in immediate 
 contact with the whole sur- 
 face of the iron chamber and 
 pipe. This air being thus 
 heated and rarified, ascends towards the head of the stove, 
 and passes through one or more apertures, e, into the room re- 
 quired to be warmed. The fuel is supplied at the door, c, and 
 passes down a sloping dead plate to the fire-bars at g. The 
 ash-pit and draught-hole for the fire are shewn at d. 
 
 In order to bring the air in contact with a greater extent of 
 heated surface, another form is sometimes given to the cockle, 
 by contracting its diameter, and bending the iron pipe into a 
 serpentine form, as shewn in Fig. 40. The fire-chamber is 
 
THE BELPER STOVE. 
 
 117 
 
 Fig. 40. formed by placing the grating near 
 
 the lower part of the conical pipe a, 
 the opening to which for the admis- 
 sion of the fuel is at c ; another nar- 
 row opening is made immediately in 
 front of the fire-bars, to allow the 
 ashes to be cleared from the bottom 
 of the fire. The brickwork, 6, en- 
 closing the cockle, is in the form of 
 a parallelogram, and the heated air 
 escapes through e, and is conducted 
 by pipes to the rooms required to be 
 heated. The following is the work- 
 ing effect of a cockle of this kind, 
 but with only one bend in the pipe, which entered the chimney 
 lower down instead of proceeding upwards to d. The cockle 
 itself was two and a quarter feet wide, six feet high, and the 
 sides three quarters of an inch thick. The brick casing was 
 at the distance of six inches from the metal, and the descend- 
 ing vent within was six inches in diameter. The stove here 
 described was used for warming a lecture-room 35 feet long, 
 27 broad, and 20 high ; also a large apartment 30 feet long, 
 27 broad, and 18 high; besides two smaller rooms and a 
 staircase. The fire was kindled during winter at seven A.M., 
 and kept burning till four P.M., when it was allowed to go out. 
 The average quantity of coals consumed was rather less than 
 half a hundred weight. The temperature of the air from the 
 tubes varied from 120 to 180, according to the state of the 
 fire. The temperature of the different apartments was kept 
 at about 60. When first erected, the supply of air for the 
 hot chamber was brought from without ; but afterwards, the 
 air for the fuel and for the hot chamber were both taken 
 from the apartment containing the stove, which was generally 
 at 70. 
 
 Mr. Strutt, of Belper, in Derbyshire, appears to have been 
 the first person who introduced the cockle-stoves, and hence, 
 
118 
 
 THE BELPER STOVE. 
 
 they are often named in honour of him Belper stoves. In 
 1792, he warmed his large cotton factories by their means j 
 but the cockle-stove, erected by Mr. Charles Sylvester for 
 warming the Derby Infirmary, was long regarded as a model 
 of its kind for a large building. In a stove of this kind, it is 
 necessary that the area be such as to allow of the subterranean 
 passage being carried out, so as to communicate with the ex- 
 ternal atmosphere at some convenient distance from the build- 
 ing, in order to admit a current of cool air for ventilation 
 during summer, as well as for the supply of the stove for 
 warming the air of the apartments in winter. The stove 
 should also be erected as near the area of the building as 
 convenient, and be placed from six to twelve feet below the 
 floor, in order to preserve uniformity as much as possible in 
 the distribution of the warm air. The cockle, a (Fig. 41), is 
 cubical in form, with a dome or groined arch top ; it is about 
 
 Fig. 41 
 
OF THE DERBY INFIRMARY. 119 
 
 three feet in diameter, and four feet high, and is made of iron 
 plates rivetted together. The smoke passes off by a narrow 
 passage at the base of the cockle through the flue /. The 
 brickwork surrounding the cockle is built with alternate open- 
 ings between the bricks, as in Fig. 41, at about eight inches 
 distant from the sides of the cockle. Through these apertures 
 are inserted pipes of sheet iron, or common porcelain-ware, so 
 as to extend within an inch of the cockle, by which means the 
 air to be heated may be thrown near, or in immediate contact, 
 with the surface of the cockle, if desirable. The horizontal 
 partition, d d, cuts oif the communication between the lower 
 and the upper portion of the air-chamber, the arched openings 
 in the lower half, c c, being the openings of the main air-flue 
 leading from the exterior atmosphere. The fire-room and ash- 
 pit are shewn at b b, and the fuel is introduced by the open- 
 ing at i. 
 
 It will be seen, from this arrangement, that the air passing 
 from the lower flues, c c, through the apertures beneath the 
 horizontal partition, and coming in immediate contact with 
 the surface of the cockle, must find its way into the upper air- 
 chamber, e e, through the numerous pipes or openings of the 
 upper division, by which circuit its velocity will be sufficiently 
 retarded to obtain the necessary elevation of temperature from 
 the heated cockle. But that the air may not be burnt, it is 
 necessary to regulate the size of the fire-chamber, so as not to 
 heat the cockle, on an average, more than 300. The Derby 
 stove allows the passage of nearly five cubic feet of air per 
 second, which is heated to about 130 at the instant it escapes 
 from the upper air-chamber into the pipes leading to different 
 parts of the building. These pipes are furnished with dampers 
 to regulate the admission of warm air at pleasure. 
 
 If care be taken to prevent the burning of the air, this 
 method of heating a large building appears to be wholesome 
 and economical. It would scarcely answer on a small scale, 
 on account of the expense of erection ; nor could it be easily 
 applied to a large building, unless constructed in the first 
 
120 MR. SYLVESTER'S STOVE. 
 
 instance, or during the erection of the edifice. The air pas- 
 sages being placed several feet below the surface of the ground, 
 affords a convenient mode of admitting a portion of cold air to 
 the interior of the building during summer, by means of a 
 revolving mouth-piece, or turn-cap, placed at the opening of 
 the air-passage, so as to receive the current of wind at the 
 outer extremity of the passage, and thus convey it to the in- 
 terior of the building. 
 
 The various objections which have been urged, from time to 
 time, against this method of warming buildings, by bringing 
 the air into contact with a surface of iron heated by fire, have 
 led to other methods of heating the metallic surface. Thus 
 Mr. John Sylvester, in his evidence before the House of Com- 
 mons' Committee, in 1835, proposed this method of warming 
 the New Houses of Parliament. An apparatus was to be 
 erected beneath the house, or on the basement, constructed of 
 cast iron, and exposing a very large surface for the contact of 
 the fresh air ; the arrangement of the surface being such as 
 to divide the supply of fresh air into a large number of very 
 small streams. The under part of the metal surfaces being 
 heated by enclosing water, or steam, the air so divided would 
 flow in contact with such warming surfaces, and thus become 
 heated to the temperature required. When thus heated, it 
 would be allowed to now under the whole area of the house, 
 the floor of which, being perforated with a multitude of holes, 
 would thus admit it into the body of the house. (See Fig. 87) 
 
 This brings us to the next step in the art of warming 
 buildings ; namely, by steam, for the details of which we refer 
 to the next Chapter. 
 
121 
 
 CHAPTER III. 
 
 ON THE WARMING OF BUILDINGS BY MEANS OF STEAM AND 
 HOT WATER. 
 
 THE method of warming buildings by steam, depends on the 
 rapid condensation of steam into water when admitted into 
 any vessel which is not so hot as itself. At the moment of 
 condensation, the latent heat of the steam is given out to the 
 vessel containing it, and this diffuses the heat into the sur- 
 rounding space. 
 
 The first practical application of this principle was made by 
 James Watt, in the winter of 1784-5, who fitted up an appa- 
 ratus for warming his study. The room was 18 feet long, 
 14 feet wide, and 8<| feet high. The apparatus consisted of a 
 box, or heater, made of two side plates of tinned iron, about 
 3^ feet long by 2^ feet wide, separated about an inch by stays, 
 and jointed round the edges by tin plate. This heater was 
 placed on its edge, near the floor of the room. It was fur- 
 nished with a cock to let out the air, and was supplied with 
 steam by a pipe from a boiler, entering at its lower edge, and 
 by this pipe, the condensed water also returned to the boiler. 
 The heating effect of this apparatus was not so great as was 
 expected, in consequence, perhaps, of the bright metallic sur- 
 faces of the box not being favourable to radiation. 
 
 In 1791, Mr. Hoyle, of Halifax, took out a patent for heat- 
 ing by steam pipes, and his method seems to have been the 
 foundation for subsequent attempts. The steam was at once 
 conveyed from the boiler, by a pipe, to the highest elevation 
 of the building required to be heated, and, from that point, by 
 a gentle declivity, the condensed water flowed into the supply 
 cistern of the boiler. The effect of the pipes (which were of 
 copper) was too small, and as the apparatus was constantly 
 getting out of order, it was pronounced a failure. 
 
 In 1793, Mr. Green took out a patent for a different method. 
 
122 EARLY FORMS OF APPARATUS 
 
 which consisted in enclosing a hollow vessel, or worm pipe, in 
 a boiler containing hot water or steam. The air, on its way 
 to the room to be warmed, was made to pass through this 
 worm, and was thus heated to an agreeable temperature. By 
 another method, pipes from a steam boiler were enclosed in 
 other pipes, and, in the interval between them, the air was 
 heated on its passage to the room. This apparatus was erected 
 in a mansion on Wimbledon Common. The encased pipe was 
 fixed along the ceiling of the basement floor, with an inclina- 
 tion of two inches in 68 feet. The inner steam pipe was three 
 inches in diameter, the outer pipe nine inches, and both of 
 copper. The lower end of the casing pipe was left open for 
 the cold air to enter ; the other end was joined to a pipe four 
 inches in diameter, with three horizontal elbows, that rose 
 about twelve inches, where it opened into the first suite of 
 rooms that were to be heated. It was supposed that the air 
 would enter at one end in great quantity, and flow out- 
 through the small pipe at the other end into the rooms } 
 the effect, however, was so feeble, that no useful heating was 
 produced. 
 
 About this time, steam was introduced into hot-houses, not 
 by circulating in pipes, but by being discharged into the body 
 of the hot-house, the effect of which was to raise its tempera- 
 ture and moisten the air to such a degree, that the plants 
 grew rapidly and luxuriantly. It is also said to have had the 
 effect of destroying insects. 
 
 In the winter of 1795-6, Mr. Boulton erected a steam heat- 
 ing apparatus in the library of his friend, Dr. Withering, 
 " which, in point of heating, answered perfectly ; but the 
 pipes being made of copper, and soft soldered in some places, 
 the smell of the solder was rather unpleasant to the Doctor, 
 who was then in an infirm state of health with diseased lungs. 
 The apparatus was, in consequence, removed to Soho, where 
 Mr. Boulton proposed erecting it in his own house, in which 
 he was making alterations about this time, and had it in view 
 to heat every room in the house by steam. A boiler was put 
 
FOE HEATING BY STEAM. 
 
 123 
 
 Fig. 42. 
 
 up for that purpose in one of the cellars, but some circum- 
 stance occurred to prevent his continuing the plan. The 
 subject, however, underwent frequent discussions, and the 
 different modes of effecting it were amply considered by Messrs. 
 Boulton and Watt, as was known to many of their friends, no 
 secret having been made, either of calculations of surface, or 
 of the modes of applying them."* 
 
 About the end of the year 1799, Mr. Lee, of Manchester, 
 under the direction of Boulton and Watt, erected a heating 
 apparatus of cast iron pipes, which served also as supports to 
 the floor. This answered perfectly, and was, in point of 
 materials and construction, the earliest of its kind. Mr. 
 Lee afterwards had his house heated by steam, and the stair- 
 case, hall, and passages, were warmed by the apparatus shewn 
 in Fig. 42. It was placed in the under- 
 ground story, and consisted of a vertical 
 cast iron cylinder, a, surrounded by a 
 casing of brick-work, leaving a space, 
 e e, of two and a half inches all round, 
 and having openings, i, below, to admit 
 the air. This casing was surrounded, 
 at the distance of three or four inches, 
 by another wall, forming a sort of well, c. 
 The colder and heavier air falling to the 
 bottom of this well, entered by the 
 holes, i t into the space, e, where it came in contact with the 
 cylinder, a, and, being heated, ascended. The entrance of the 
 steam into the cylinder was regulated by a valve, the air being 
 allowed to escape by a stop-cock, while the steam was entering; 
 the condensed water escaping by a pipe not shewn in the 
 figure. The transmission of the heated air was regulated by 
 a valve at a, on the top of the brick-work. This apparatus 
 was so effective, and heated the staircase to such a degree, that 
 after it had been in operation a short time, it was necessary 
 
 c 
 
 1 
 
 
 1 
 
 31 
 
 1 
 
 
 c 
 
 I 
 
 
 
 c 
 
 
 e 
 
 
 
 
 
 
 0. 
 
 
 
 
 
 i 
 
 
 
 
 
 i 
 
 
 Buchanan on the Economy of Fuel, cfcc., 1810. Second Edition, 1815. 
 
124 EXPENDITTJBE OF THE HEAT 
 
 to suspend its action by closing the valve at a, or by closing 
 the valve which admitted steam into the cylinder. 
 
 The method of heating buildings by steam has scarcely 
 advanced since the time when Messrs. Boulton and Watt 
 erected their apparatus for the purpose, and Mr. Buchanan 
 wrote a practical treatise on the subject. The hot-water 
 apparatus has, for the most part, superseded the steam appa- 
 ratus, so that our details need not be very full. 
 
 In establishments where a steam-engine is in daily use, the 
 steam pipes may be supplied from the engine boiler, its dimen- 
 sions being enlarged at the rate of one cubic foot for every 
 2,000 cubic feet of space, to be heated to the temperature of 
 70 or 80. A boiler adapted to an engine of one-horse power, 
 is sufficient for heating 50,000 cubic feet of space. Hence an 
 apparatus specially erected for the purpose, need not be of very 
 large size, nor is the quantity of fuel consumed great. If the 
 fire under a small boiler be carefully managed, 141bs. of New- 
 castle coal will convert one cubic foot of water at 50, into 
 1,800 cubic feet of steam at 216; and only 121bs. of coal 
 are required to convert the same quantity of water into steam 
 at 212. The shape of the boiler, and the method of setting 
 it, must also be considered, and the furnace must be arranged 
 so as to admit no more air than is required to support the 
 combustion. The hot air must also be kept in contact with 
 the sides of the boiler, until as much of the heat as possible be 
 abstracted from it. In such an arrangement, according to 
 Dr. Arnott, nearly half of all the heat produced in the com- 
 bustion is applied to use. 
 
 In estimating the extent of surface of steam pipe required 
 to raise the rooms to the proper temperature, it is necessary 
 to consider how the heat is expended. This is done in three 
 ways : 1, Through the thin glass of the windows. 2, More 
 slowly through the walls, floors, and ceiling ; and 3, In com- 
 bination with the air which escapes at the joinings of the win- 
 dows and doors, or through openings expressly made for the 
 purpose of ventilation. The amount of heat lost in this way 
 
IN WARMING BY STEAM. 125 
 
 has been variously estimated by different writers, but Dr. Ar- 
 nott states it thus : That in a winter day, with the external 
 temperature at 10 below freezing, to maintain in an ordinary 
 apartment the agreeable and healthful temperature of 60, 
 there must be of surface of steam pipe, or other steam vessel 
 heated to 200 (which is the average surface-temperature of 
 vessels filled with steam of 212), about one foot square for 
 every six feet of single glass window of usual thickness ; as 
 much for every 120 feet of wall, roof, and ceiling of ordinary 
 material and thickness ; and as much for every six cubic feet 
 of hot air escaping per minute as ventilation, and replaced by 
 cold air. A window, with the usual accuracy of fitting, 
 allows about eight feet of air to pass by it in a minute, and 
 there should be for ventilation, at least three feet of air per 
 minute for each person in the room. According to this view, 
 the quantity of steam pipe, or vessel, needed, under the tem- 
 perature supposed, for a room 16 feet square by 12 feet high, 
 with two windows, each 7 feet by 3, and with ventilation, by 
 them or otherwise, at the rate of sixteen cubic feet per minute, 
 
 would be 
 
 Feet. 
 
 For 42 square feet of glass (requiring 1 foot for 6). . 7 
 1,238 feet of wall floor and ceiling (requiring 
 
 1 foot for 120) 10 
 
 ,,16 feet per minute for ventilation (requiring 1 
 
 foot for 6) 2| 
 
 Total of heating surface required 20 
 
 Which is 20 feet of pipe, 4 inches in diameter, or any other 
 vessel having the same extent of surface, as a box two feet 
 high, with square top and bottom of about eighteen inches. It 
 may be noticed, that nearly the same quantity of heated sur- 
 face would suffice for a larger room, provided the quantity of 
 window glass, and of the ventilation, were not greater ; for 
 the extent of wall, owing to its slow conducting quality, pro- 
 duces comparatively little effect. 
 
126 ARRANGEMENT OP THE APPARATUS 
 
 The same excellent authority also supplies the following 
 illustrations : A heated surface, as of iron, glass, &c., at tem- 
 peratures likely to be met with in rooms, if exposed to colder 
 air, gives out heat with rapidity, nearly proportioned to the 
 excess of its temperature above that of the air around it, less 
 than half the heat being given out by radiation, and more than 
 half by contact of the air. Thus, if the external surface of an 
 iron pipe, heated by steam, be 200, while the air of the room 
 to be warmed by it, is at 60, shewing an excess of temperature 
 in the pipe of 140, such pipe will give out nearly seven times 
 as much heat in a minute as when its temperature falls to 
 80, because the excess is reduced to 20, or -i- of what it was. 
 Supposing window glass to cool at the same rate as iron plate, 
 one foot of the steam pipe would give out as much heat as 
 would be dissipated from the room into the external air by 
 about five feet of window, the outer surface of which were 30 
 warmer than that air. But as glass both conducts and radiates 
 heat about \ slower than iron, the external surface of the glass 
 of a window of a room, heated to 60, would, in an atmosphere 
 of 22, be under 50, leaving an excess of less than 30 ; and 
 about six feet of glass would be required to dissipate the heat 
 given off by one foot of the steam pipe. In double windows, 
 whether of two sashes, or of double panes, only half an inch 
 apart in the same sash, the loss of heat is only about one-fourth 
 of what it is through a single window. It is also known that 
 one foot of black or brown iron surface, the iron being of 
 moderate thickness, with 140 excess of temperature, cools in 
 one second of time 156 cubic inches of water, one degree. 
 From this standard fact, and the law above given, a rough cal- 
 culation may be made for any other combination of time, 
 surface, excess, and quantity. And it is to be recollected, that 
 the quantity of heat which changes, in any degree, the tempe- 
 rature of a cubic foot of water, produces the same change on 
 2,850 cubic feet of atmospheric air. 
 
 The arrangement of the steam pipes has next to be con- 
 sidered. A common method is shewn in Fig. 43, in which 
 
IN WARMING BY STEAM. 
 
 127 
 
 Fig. 43. 
 
 a is the pipe from the boiler, rising 
 at once to the upper story. From 
 this pipe proceed horizontal branch- 
 es, b b, to each floor. Each branch 
 is furnished with a stop -cock at o, 
 by which means the steam can be 
 turned on or off at pleasure, in any 
 one of the three stories. The water 
 arising from the condensation of the steam in each pipe, flows 
 back into the boiler along the ascending pipe. But if it be 
 not convenient to place the boiler below the level of the lowest 
 floor, the condensed steam is received into a reservoir, from 
 which it is pumped into the feeding cistern. At the extremity 
 of each horizontal branch, c, is a stop-cock, which is opened, 
 when the steam is filling, to allow the air to blow off. 
 
 Another arrangement of the heating pipes is shewn in 
 Fig. 44. Fig. 44. Steam from the boiler 
 
 enters by the connecting pipe, a } 
 into the heating pipe, b, placed near 
 the floor, and this is carried, with a 
 gentle slope, to the opposite side of 
 the room, whence it rises into the 
 next story, and returns along its 
 floor to the opposite side, where it 
 rises to the third floor, and proceeds as before. Here, also, 
 the condensed water flows back in a direction contrary to the 
 current of the steam, and is removed by a siphon at a. The 
 air-vent is fixed at the highest point of the arrangement, c. 
 
 It is necessary to prevent the condensed water from accu- 
 mulating in the pipes, otherwise it would be impossible to 
 maintain them at a uniform temperature. Moreover, this 
 water condenses the steam so rapidly, that a vacuum is formed 
 within the boiler and pipes ; and should they not be firm 
 enough to resist the external pressure of the atmosphere, the 
 boiler may be crushed in, and the whole system deranged. By 
 a special arrangement, the condensed water is collected at 
 
128 
 
 SIPHON AND STEAM TRAP 
 
 Fig. 45. 
 
 certain parts of the system, where it continues to give out heat 
 after the steam has ceased to flow into the pipes. In such 
 cases, stop-cocks may be employed, so arranged as to allow the 
 water to be afterwards withdrawn from the pipes ; the same 
 cocks also serve for letting the air out of the pipes when the 
 steam is first admitted ; but when the water is returned into 
 the boiler, the advantage of this supply of heat cannot be 
 reserved ; and in these cases, a self-acting apparatus is used 
 for taking off the water of condensation. Such a siphon is 
 represented in Fig. 45. The pipes 
 are so fixed, that A is the lowest 
 point of a branch pipe, so that any 
 quantity of water that may be formed 
 in it, will flow into the siphon, ABC, 
 at A, and escape at c, where it may 
 be received into any vessel, for as the 
 water is pure distilled water, it may 
 be useful for a variety of purposes. 
 The water in the legs of the siphon 
 acts as a trap to the steam in the 
 pipe, A ; hence, the length of the leg ? 
 A B, should not be less than is equiva- 
 lent to the force of the steam in the 
 pipes. When, for example, the steam 
 is worked at the rate of ten pounds 
 per square inch, the column of water 
 should not be less than ten feet, and 
 even with this pressure, there will be considerable oscillations, 
 unless a valve be placed at some intermediate point between A 
 and B. When the legs are both filled with water, and at rest, 
 this valve should be open, so as to close whenever the water 
 has a tendency to return into the pipe. The siphon should be 
 large enough to carry oiF all the water of condensation, but 
 not too large, or there would be a loss of heat in the leg, A B, 
 from its being filled with steam j and, in all cases, the siphon 
 should be protected from frost. In connection with the siphon,, 
 
FOR THE CONDENSED WATER. 
 
 129 
 
 Fig. 46. 
 
 it is usual to place a cock for letting the air out of the 
 pipe, instead of the stop-cock above referred to. Such a cock 
 is shewn at B, and it is made to range with the lower part of 
 the pipe, because the air being heavier than steam, will occupy 
 only the lower portion of it. 
 
 In cases were sufficient depth cannot be afforded for a siphon, 
 a steam trap, or valve, made to open by a float ball, is employed. 
 
 Tredgold's arrangement is 
 as follows : B c (Fig. 46), 
 is a square box attached to 
 the end, A, of the steam- 
 pipe ; D is a hollow copper 
 cylinder, fixed to a conical 
 valve, E; when steam is 
 condensed, the square box 
 will fill with water, which 
 will float the hollow cylin- 
 der, and the water will 
 escape, and run by the 
 pipe, F, into the drain; 
 whenever the quantity of 
 water in the box is greater 
 than is required just to float the cylinder, and when there is 
 less than will float it, the valve will be closed. In this case 
 also, a stop cock, s, will be necessary to let out the air while 
 the pipes are being filled with steam. 
 
 The various methods of connecting the cast iron pipes are by 
 the flange joint, and the spigot and faucet, or socket joint. Mr. 
 Buchanan gives minute directions for these, but he seems inclined 
 to recommend the thimble joint. Care must, of course, be taken 
 in joining the pipes, to allow room for expansion. This is some- 
 times done in the thimble joint (Fig. 47), in 
 which the adjoining ends of the pipes, a i, 
 are turned true on the outside, and have a 
 thimble, or short cylinder of wrought iron, 
 to enclose them, leaving only a small space 
 G 5 
 
 Fig. 47. 
 
130 METHODS OF JOINING THE PIPES. 
 
 for the current. A piece of tin, c, or inner thimble, is inter- 
 posed, and made to fit well to the turned parts of the pipes, 
 which, under the influence of heat or cold, work forwards or 
 backwards, like a piston in a cylinder. In a range of pipes 120 
 feet in length, there was a motion from expansion of three 
 quarters of an inch j but the usual allowance for the expansion 
 of cast iron pipes, is one eighth of an inch in 1 feet, or -^ 
 of their length. Cast iron, heated from 32 to 212, expands 
 -gj^ of its length, which is nearly one and three eighths of an 
 inch in 100 feet. A similar expansion joint applied to the 
 Fig. 48. spigot and faucet connection (Fig. 48), answered 
 
 very well. Lead cannot be substituted for tin 
 or iron cement in joints, for, by frequent heat- 
 ing, it becomes permanently expanded, while 
 the iron pipes always contracting in cooling, 
 and the lead not participating in the contraction, the joints 
 soon get loose. Count Rumford introduced an expansion drum, 
 x (Fig. 49), of thin copper, [between the extremities of two 
 Fig. 49. pipes, a i, which, in elongating, pressed the 
 
 sides of the drum inwards, and in cooling 
 drew them outwards. The pipes should not 
 be connected with any part of the building, 
 but be quite independent thereof; all the 
 horizontal branches should be supported on 
 rollers, and nothing done to interfere with 
 the expansion of the different parts. 
 In private dwellings, where the appearance of the pipes is 
 objectionable, they may be concealed behind perforated mould- 
 ings, or skirtings, or cornices ; or the steam may be brought 
 into ornamental vases dispersed about the room, each furnished 
 with a small stop-cock, to allow the air to escape while the 
 steam is entering. 
 
 The method of heating buildings by steam has been long 
 superseded by hot water apparatus of various kinds, which, 
 however, may be resolved into two distinct forms or modifica- 
 tions, dependant on the temperature of the water. In the 
 
WARMING BY HOT WATER. 131 
 
 first form of apparatus, the water is at or below the ordinary 
 temperature of boiling. In this arrangement the pipes do not 
 rise to any considerable height above the level of the boiler, so 
 that the apparatus need not be of extraordinary strength. One 
 pipe rises from the top of the boiler, and traverses the places 
 to be warmed, and returns to terminate near the bottom of the 
 boiler. Along this tube the heated water circulates, giving 
 out its heat as it proceeds. The boiler may be open or 
 closed. If open, the tube, when once filled with water, acts 
 as a siphon, having an ascending current of hot water in the 
 shorter leg, and a descending current of cooled water in the 
 longer leg. If the boiler be closed, the siphon action disap- 
 pears, and the boiler with its tubes become as one vessel. In 
 the second form of apparatus, the water is heated to 350 and 
 upwards, and is, therefore, constantly seeking to burst out as 
 steam, with a force of TOlbs. and upwards on the square 
 inch, and can only be confined by very strong or high pressure 
 apparatus. The pipe is of iron, about an inch in diameter, 
 made very thick. The length extends to 1,000 feet and 
 upwards, and where much surface is required for giving out 
 heat, the pipe is coiled up like a screw. A similar coil is also 
 surrounded by the burning fuel, and serves the place of a oiler. 
 The heating of rooms by the circulation of hot water in 
 pipes, seems to have occupied the attention of a few speculative 
 individuals, long before the attempt was actually made. The 
 first successful trial is assigned to Sir Martin Triewald, a Swede, 
 who resided for many years at Newcastle-on-Tyne, and about 
 the year 1716, described a method for warming a greenhouse 
 by hot water. The water was boiled outside the building, and 
 then conducted by a pipe into a chamber under the plants. 
 
 But the first successful attempt, on a large scale, was made 
 in France, in 1777, by M. Bonnemain, in an apparatus for 
 hatching chickens, for the purpose of supplying the market of 
 Paris. A section of this heating apparatus is shewn in Fig. 50, 
 in which a is the boiler, d a feed-pipe, o a stop-cock, for 
 regulating the quantity of ascending hot water, 6 the 
 
132 
 
 BONNEMAIN'S APPARATUS. 
 
 pipe by which the hot water ascends from the boiler into 
 the heating pipes, c c, which traverse the hatching cham- 
 ber. These heating pipes 
 hare a gradual slope towards 
 the boiler, to which the water 
 returns by the pipe, e, carried 
 nearly to the bottom. In this 
 way the water, cooled by being 
 circulated through a long 
 series of pipes, is being con- 
 stantly returned to the lowest part of the boiler, where it receives 
 a fresh amount of heat, and being thus rendered lighter, rises up 
 the pipe, b, and descends the inclined planes of the pipes, losing 
 a portion of its heat on the way, and at the same time increas- 
 ing in density ; the velocity of the current depending on the 
 difference between the temperature of the water in the boiler, 
 and that in the descending pipe. At the highest point of the 
 apparatus is a pipe, i, furnished with a stop-cock for the escape 
 of the air which the cold water holds in solution on entering 
 the boiler. The water that rises along with it is received 
 into the vessel L 
 
 The arrangements of this apparatus are excellent ; they 
 have been taken as a model in many subsequent methods, 
 although the merits of the inventor have not always been 
 acknowledged. The plan was introduced into this country in 
 1816, by the Marquis de Chabannes, who was long regarded 
 as the inventor. About the year 1822, Mr. Bacon and Mr. 
 Atkinson introduced modifications of the apparatus, but the 
 latter gentleman succeeded in reducing it to its most simple 
 and practical form. 
 
 Whatever be the arrangement adopted for warming build- 
 ings by this method, two considerations must be specially 
 attended to, namely, sufficient strength to bear the hydrostatic 
 pressure, and freedom of motion for currents of water, of vary- 
 ing temperatures, and consequently of varying densities. As 
 fiuids transmit their pressure equally in every direction, a 
 
CIRCULATION OP THE WATER. 133 
 
 column of water rising from a strong vessel to a certain height, 
 may be made to burst the vessel with enormous force. Thus 
 a tube whose sectional area is one inch, rising to the height of 
 344 feet from the bottom of a vessel of water, will, if the tube 
 be also full of water, exert a bursting pressure on every square 
 inch of the inner surface of such vessel of one atmosphere, or 
 151bs. If the sectional area of the tube be increased, the pres- 
 sure remains the same, because it is distributed over a larger 
 surface of the vessel. If a boiler be 3 feet long, 2 feet wide, 
 and 2 feet deep, with a pipe 28 feet high from the top of the 
 boiler, when the apparatus is filled with water, there will be a 
 pressure on the boiler of 66,81 61bs. or very nearly 30 tons. 
 This will shew the necessity for great strength in the boiler, 
 especially when it is considered that the effect of heat upon it 
 is to diminish the cohesive force of its particles. But even 
 supposing the apparatus were to burst, no danger would arise, 
 because water, unlike steam, has but a very limited range of 
 elasticity. The boiler just described would contain about 75 
 gallons of water, which under a pressure of one atmosphere on 
 the square inch would be compressed about one cubic inch ; 
 and if the apparatus were to burst, the expansion would only 
 be one cubic inch, and the only effect of bursting, would be a 
 cracking in some part of the boiler, occasioning a leakage of the 
 water. 
 
 The circulation of the water is brought about by the princi- 
 ple of convection already explained in the case of air (page 31). 
 When heat is applied to a vessel containing water, the prin- 
 ciple of conduction altogether fails, for water is so imperfect 
 a conductor of heat, that if the fire be applied at the top, the 
 water may be made to boil there without greatly affecting the 
 temperature below. But when the fire is applied below the 
 particles in contact with the bottom of the boiler, being first 
 affected by the heat, expand, and thus becoming specifically 
 lighter than the surrounding particles, ascend, and other par- 
 ticles take their place, which in like manner becoming heated, 
 ascend also ; and the process goes on in this way until the 
 
134 FORCE WITH WHICH THE WATER 
 
 whole contents of the boiler have received an accession 
 of temperature. If the process be continued long enough, the 
 water will boil and pass off in steam j if the boiler be closed 
 in on all sides, so as to prevent the escape of steam, it will 
 burst with a fearful explosion. If a tube full of water rise 
 from the top of the boiler in a vertical line to any required 
 height, and then by a series of gentle curves descend, and 
 enter near the bottom of the boiler, the process of heating is 
 still the same. The particles of water first heated will rise, 
 and, in doing so, distribute their heat to other particles, which 
 will also rise ; these in their turn will lose a portion of their 
 heat to other particles, which rise in their turn; until at length 
 an equilibrium is established. But as the source of heat is 
 permanent, other particles are rapidly brought under its action, 
 and, being heated, ascend. By continuing the process a short 
 time, the particles in the vertical tube become heated, and, by 
 their expansion, exert a pressure on the water contained in the 
 lateral branches ; this, together with the increasing levity of 
 the water in the boiler, establishes a current, and the water 
 from the branches begins to set in, in the direction of the 
 boiler ; the water in the lowest branch, where it enters the 
 boiler, supplying colder and heavier particles every moment to 
 take the place of the warmer and lighter particles which are 
 being urged upwards along the vertical pipe. 
 
 Now to ascertain the force with which the water returns to 
 the boiler, we must know the specific gravities of the two 
 columns of water, the ascending and the descending, and the 
 difference between them will be the effective pressure, or motive 
 power. This can be done by ascertaining the temperature of 
 the water in the boiler, and in the descending pipe. When 
 the difference amounts to only a few degrees, the difference in 
 weight is very small, but quite sufficient in a well arranged 
 apparatus to maintain a constant circulation. For example, 
 suppose an apparatus to be at work, in which the temperature 
 in the descending pipe is 170, and the temperature of the 
 water in the boiler, the height of which is 12 inches, is 178, 
 
CIRCULATES IN HOT- WATER PIPES. 135 
 
 The difference in weight is 8. 1 6 grains on each square inch of 
 the section of the return pipe. If the boiler, A (Fig. 51), be 
 two feet high, and the distance from the top of the upper 
 pipe, c, to the centre of the lower pipe, d, be 18 inches, and 
 the pipe four inches in diameter, the difference of pressure on 
 the return pipe will be 153 grains, or about one-third of an 
 ounce weight, and this will be the amount of motive power of 
 the apparatus, whatever be the length of pipe attached to it. 
 
 If such an apparatus have 100 
 yards of pipe, four inches in 
 diameter, and the boiler con- 
 tain 30 gallons, there will 
 be 190 gallons or l,9001bs. 
 weight of water kept in continual motion by a force equal to 
 only one-third of an ounce.* 
 
 The amount of motive power increases with the size of the 
 pipe. The power being four times as great in a pipe of four 
 inches in diameter as in one of two inches, as the former con- 
 tains four times as much water as the latter ; but as the resist- 
 ance increases equally with the power, the actual working effect 
 is the same in pipes of all sizes. The motive power is increased 
 by allowing the water to cool before it returns to the boiler, 
 or by increasing the height of the ascending and descending 
 columns of water. By doubling the difference of temperature 
 between the flow-pipe and the return-pipe, the same increase 
 of power is obtained as by doubling the vertical height ; and 
 by tripling the difference in temperature, the same effect is 
 produced as by tripling the vertical height. The difference 
 in temperature may also be increased by increasing the quan- 
 tity of pipe, or by diminishing its diameter, so as to expose a 
 
 * Mr. Hood in his Treatise on Warming Buildings by Hot Water, 
 <kc., gives a table shewing the difference in weight of two columns of 
 water, each one foot high, at various temperatures. The writer takes 
 this opportunity of expressing his obligations to this valuable work, to 
 which he refers the reader who desires to master the subject on which it 
 treats. 
 
136 CIRCULATING FORCE OF THE WATER. 
 
 larger amount of surface, in proportion to the quantity of 
 water contained in it, so as to allow it to part with more heat 
 within a given time. But the method which must be princi- 
 pally depended on, when additional power is required to over- 
 come any unusual obstruction, is to increase the height of the 
 ascending column. 
 
 Another method of estimating the velocity of motion of the 
 water of a hot-water apparatus, is to regard the two portions 
 of the system, as the lighter and heavier fluids in the two 
 limbs of a barometrical aeriometer. This instrument is an 
 Fig. 52. inverted siphon, Fig. 52, and its use is to ascer- 
 tain, in a rough way, the specific gravities of immis- 
 cible fluids. If mercury be poured into one limb' 
 A, and water into the other, B, and the stop-cock 
 at c be turned, so as to establish a communication 
 between them, it will be found that an inch of 
 mercury, F D, in one limb will balance thirteen-and- 
 a-half inches of water, i E, in the other limb ; thus 
 shewing that the densities, or specific gravities, of 
 the two fluids, are as thirteen-and-a-half to one. 
 If oil be used instead of mercury, it will require 
 ten inches of oil to balance nine inches of water. 
 Or if equal bulks of oil and water be poured into 
 the limbs of the siphon, and the stop-cock be then turned, the 
 oil will be forced upwards with a velocity equal to that which 
 a solid body would acquire in falling by its own gravity, 
 through a space equal to the additional height which the 
 lighter body would occupy in the siphon. Now as the rela- 
 tive weights of water and oil are as nine to ten, the oil in one 
 limb will be forced upwards by the water with a velocity equal 
 to that which a falling body (in this case, the water) would 
 acquire in falling through one inch of space, and this velocity 
 is equal to 138 feet per minute. 
 
 In estimating the velocity of motion of the water in a hot- 
 water apparatus, the same rule will apply. " If the average 
 temperature be 170, the difference between the temperature 
 
EFFECTS OF FRICTION. 137 
 
 of the ascending and descending columns 8, and the height 
 ten feet ; when similar weights of water are placed in each 
 column, the hottest will stand .331 of an inch higher than the 
 other; and this will give a velocity equal to 79.2 feet per minute. 
 If the height be five feet, the difference of temperature remain- 
 ing as before, the velocity will be only 55.2 feet per minute ; 
 but if the difference of temperature, in this last example, had 
 been double the amount stated ; that is, had the difference 
 of temperature been 16, and the vertical height of the pipe 
 five feet, then the velocity of motion would have been 79.2 
 feet per minute, the same as in the first example, where the 
 vertical height was ten feet, and the difference of temperature 
 8." 
 
 But, in all these calculations, a considerable deduction must 
 be made for the effects of friction. In the centre of the 
 ascending pipe, the heated particles meet with the smallest 
 amount of obstruction, and there the motion is quickest ; but 
 at and near the circumference of the pipe, the retarding 
 effects of friction are most apparent. In the descending pipe 
 the friction is less, for the water descends more as a whole, 
 and is, moreover, assisted by the gravity of the mass. In an 
 apparatus, where the length of pipe is not great, where the 
 pipes are of large diameter, and the bends and angles few, a 
 large deduction from the theoretical amount must still be 
 made, to represent, with anything like accuracy, the true 
 velocity ; and Mr. Hood states, that in more complex appara- 
 tus, the velocity of circulation is so much reduced by friction, 
 that it will sometimes require from 50 to 90 per cent., and 
 upwards, to be deducted from the calculated velocity, in order 
 to obtain the true rate of circulation. 
 
 The amount of friction not only varies according to the 
 arrangement of the apparatus, but also according to the size 
 of the pipes. It is much greater in small pipes than in 
 large ones, on account of the relatively larger amount of sur- 
 face in the former ; besides this, small pipes cool quicker than 
 large ones, and this increases the velocity of the circulation, 
 
138 
 
 PRECAUTIONS REQUIRED IN 
 
 and with it, the friction is also increased. When the velocity 
 with which the water flows, is the same in pipes of different 
 sizes, the relative amount of friction is as follows : 
 
 Diameter of the pipes, ^ inch, 1 in. 2 in. 3 in. 4 in. 
 The amount of friction, 8, 4, 3, 1.3, 1. 
 
 So that, if the friction in a pipe of 4 inches diameter be 
 represented by 1, the friction of a pipe 2 inches in diameter 
 is twice as much, and a 1-inch pipe four times as much. By 
 increasing the velocity, the friction increases nearly as the 
 square of the velocity ; but as the water in a hot- water appa- 
 ratus circulates with various degrees of speed in its different 
 parts, it is not easy to calculate the amount of friction from 
 this cause. 
 
 It will be seen, then, that when all the deductions are made, 
 the circulation of the water is produced by a very feeble power, 
 so that, as may be supposed, a very slight cause is sufficient 
 to neutralise it. Mr. Hood has known so trifling a circumstance 
 as a thin shaving accidentally getting into a pipe, effectually 
 to prevent the circulation in an apparatus otherwise perfect in 
 all its parts. 
 
 But the great point to be attended to, is so to dispose the 
 pipes, that the water, in its descent, may not be obstructed by 
 differences of level, or angles in the pipes, where air may 
 accumulate ; for this, by dividing the stream, effectually pre- 
 vents the circulation. For example, in an apparatus constructed 
 
 in the form represented in 
 Fig. 53, the motion through 
 the boiler and pipe, A B, takes 
 place by convection, and 
 through the descending pipe, 
 c D, by the force of gravity, 
 as already described. But? 
 it will be seen, that when the 
 motion commences in the return pipe, D B, in consequence of 
 the greater pressure of c D than of A B, the water in A will be 
 
 Fig. 53. 
 
THE ARRANGEMENT OF THE PIPES. 139 
 
 forced towards e } while the water in efg h flows towards c. 
 But when a very small quantity of hot water has passed from 
 the pipe and boiler, A B, into the pipe ef } the column of water, 
 g h, will be heavier than the column ef, and the current will, 
 therefore, tend to move along the upper pipe towards the 
 boiler, instead of from it. This force, whatever its amount, 
 must oppose that in the lower or return pipe, in consequence 
 of the pressure of c D being greater than A B ; and unless the 
 force of motion in the descending pipe, o D, be sufficient to 
 overcome this tendency to a retrograde motion, and leave a 
 residual force sufficient to produce direct motion, no circulation 
 of the water can take place. 
 
 With respect to the accumulation of air in the pipes, every 
 part of the apparatus, where an alteration of level occurs, must 
 be furnished with a vent for the air. Thus, in Fig. 53, if the 
 air accumulate in the pipe between A and e, it is evident that 
 a vent at c, although it would take off the air from g h, and 
 from c D, could not receive any portion of that which is con- 
 fined between A e, or between ef, because, in that case, it must 
 descend through the pipe, ef, before it could escape, and as 
 air is so very much lighter than water, it cannot possibly 
 descend so as to pass an obstruction lower than the place 
 where it is confined. The same remark applies to all cases, 
 however large or small the descent may be, and the accidental 
 misplacing of a pipe in the fixing, by which one end may be 
 made a little higher than the other, will as effectually prevent 
 the escape of air through a vent placed at the lower end, as 
 though the deviation from the level were as many feet as it 
 may, perhaps, be inches. 
 
 When it is required to heat a number of separate stories by 
 the same boiler, one of two methods may be adopted. The 
 vertical pipe from the boiler may be carried up to the highest 
 story, and the return pipe meander through each story, until it 
 finally terminates in the boiler. But it is obvious, that in 
 such case, the top story will get the larger share of the heat, 
 and the lower stories will be gradually less heated, on account 
 
HO 
 
 PRECAUTIONS REQUIRED IN 
 
 Fig. 54. 
 
 of the cooling of the water in its passage to the boiler. The 
 second method is to supply each story with a separate range 
 of pipes branching out from the main pipe, and returning 
 either together, or separately, into the boiler. The appli- 
 cation of this principle, however, requires caution, for if the 
 branch pipes are simply inserted into the side of a vertical 
 ascending pipe, the hot current may pass by, instead of flow- 
 ing into, them. Some contrivance is, therefore, necessary to 
 delay the motion of the upward current, and to cause it to 
 turn aside at the points required. This may be done by the 
 arrangement shewn in Fig. 54, which is also copied from 
 
 Mr. Hood's work. Here it will 
 be perceived, that as the water 
 ascends from the boiler, B, it 
 receives a check at 6, whereby 
 it tends to flow through the 
 horizontal pipe, at that level. 
 The same also occurs at c, and, 
 by this means, a nearly equal 
 flow of hot water may be ob- 
 tained. If it be required to 
 cut off the supply of heat from 
 one story, while the others 
 are being heated, this may 
 done by turning a stop-cock at 
 s, by which the heated current 
 is prevented from flowing along 
 the particular branch so closed. But whenever a branch is 
 closed as at s, it is necessary also to close the other end, t, of the 
 same branch, otherwise the water in the descending return 
 pipe, R, being warmer and lighter than that in the branch 
 closed at s, will circulate therein, and thus raise the tempera- 
 ture of the room intended to be kept cool. 
 
 In some arrangements, the hot ascending current of the 
 vertical main is made to discharge into an open cistern at the 
 top, as in Fig. 55, and from the bottom of this cistern the 
 
THE ARRANGEMENT OF THE PIPES. 141 
 
 Fig. 55. various flow pipes are 
 
 made to branch off. By 
 this means, the expense 
 of cocks or valves is 
 avoided; for by driving 
 a wooden plug into one 
 or more of the pipes 
 which open into the cis- 
 tern, the circulation will 
 be stopped until the apparatus is heated j but, in that case, 
 water will flow back through the return pipe. This, however, 
 may be prevented, by bending a lower portion of the return 
 pipe into the form of an inverted siphon, as shewn in the figure. 
 This will not prevent the circulation when the flow-pipe is 
 open ; but if that be closed by a plug in the cistern, the hot 
 water will not return back through the lower pipe. Any 
 sediment that may accumulate in the siphon may be removed, 
 from time to time, by taking off the cap at the lower part of 
 the bend. 
 
 In such an arrangement as that shewn in the last two 
 figures, the vertical main pipe need not be of larger diameter 
 than the branches, unless these extend to a very considerable 
 distance, and then the diameter of the main pipe may be some- 
 what enlarged. It is not, however, desirable to increase the 
 diameter of the main, because it is an object to economise the 
 heat in this pipe, and there are circumstances in which a small 
 main loses less heat than a large one, as, for example, in the 
 arrangement shewn in Fig. 55. If one main pipe, eight inches 
 in diameter, supply four branches in a given time, it is evident, 
 that by reducing the main to four inches in diameter, the 
 water must travel four times faster through the smaller pipe to 
 perform the same amount of work ; and, under such circum- 
 stances, the water will lose only half as much heat in passing 
 through the small main as it would do in ascending the larger 
 one, for the loss of heat sustained by the water is directly as 
 the time and the surface conjointly. 
 
142 SIZE OF THE PIPES REQUIRED. 
 
 Hence, in warming by the same boiler two rooms separated 
 from each other by a considerable distance, the pipe connect- 
 ing the two rooms may be of smaller diameter than the pipes 
 used for diffusing the heat. Thus a pipe of one inch diameter 
 may be used to connect pipes four inches in diameter. 
 
 The great specific heat of water, whereby it is enabled to 
 retain its heat for a very long time, has been already shewn 
 (page 42) to be a great advantage of this method of warming 
 buildings. The rate at which this apparatus cools, depends 
 chiefly on the quantity of water contained in it with respect to 
 the amount of surface exposed, and the excess of temperature 
 of the apparatus above that of the surrounding air ; but for 
 temperatures below the boiling point, this last circumstance 
 need only be taken into account in estimating the velocity with 
 which this apparatus cools. Now the variation in the rate of 
 cooling for bodies of all shapes, is inversely as the mass divided 
 by the superficies. In cylindrical pipes, the inverse number 
 of the mass divided by the surperficies is exactly equal to the 
 inverse of the diameters ; so that, supposing the temperature 
 to be the same in all, 
 
 In pipes of . . .1234 inches diameter, 
 
 The ratio of cooling will be 4 2 1.3 1 
 
 That is, a pipe of one inch in diameter will cool four times as 
 quickly as a pipe of four inches in diameter, and so on. These 
 ratios multiplied by the excess of heat in the pipes above that 
 of the surrounding air, will give the relative rates of cooling 
 for different temperatures below 212; but if the temperatures 
 be the same in all, the simple ratios given above will shew 
 their relative rate of cooling without multiplying by the 
 temperatures. 
 
 These calculations supply practical rules for estimating the 
 size of the pipes under different circumstances. If the heat 
 be required to be kept up long after the fire is extinguished, 
 large pipes should be used ; if, on the contrary, the heat is not 
 wanted after the fire is put out, then small ones will answer 
 the purpose. Pipes of larger diameter than four inches should 
 
LOSS OF HEAT ESTIMATED. 143 
 
 never be used, because they require a very long time in being 
 heated to the proper temperature. Pipes of four inches in 
 diameter are well adapted for hot-houses, green-houses, and 
 conservatories. Pipes of two or three inches may be used for 
 warming churches, factories, and dwelling-houses j such pipes 
 retain their heat for a sufficient length of time, and they can 
 be more quickly and more intensely heated than larger pipes, 
 so that, on this account, a smaller quantity of pipe will often 
 suffice. 
 
 With respect to the quantity of pipe required for warming 
 a building of ascertained size, it is necessary to bear in mind 
 the rate at which a given quantity of hot water, in an iron 
 pipe, will impart its heat to the surrounding air. Now, it 
 has been shewn by Mr. Hood, that the water contained in an 
 iron pipe four inches in diameter internally, and four and a half 
 inches externally, loses .851 of a degree of heat per minute 
 when the excess of its temperature is 125 above that of the 
 surrounding air ; and, as one cubic foot of water in losing 1 of 
 its heat will raise the temperature of 2,990 cubic feet of air 
 the like extent of 1, so one foot length of four-inch pipe will 
 heat 222 cubic feet of air 1 per minute, when the difference 
 between the temperature of the pipe and the air is 125. 
 
 We must now take into account the loss of heat per minute 
 arising from the cooling power of glass, ventilation, radiation, 
 cracks in doors and windows, and other causes. An allowance of 
 from three and half to five cubic feet of air ought to be made 
 per minute for each person in the room, so that, for the pur- 
 poses of respiration, this quantity will have to be discharged, 
 and an equal supply of air brought in to be warmed. 
 
 One square foot of glass will cool 1.279 cubic feet of air as 
 many degrees per minute as the internal temperature of the 
 room exceeds the temperature of the external air. If the 
 difference between them be 30, the 1.279 cubic feet of air 
 will be cooled 30 by each square foot of glass, that is, as 
 much heat as is equal to this will be given off by each square 
 foot of glass. 
 
144 QUANTITY OF PIPE REQUIRED. 
 
 From these and other calculations, for which we must refer 
 to Mr. Hood's able work, the following corollary is drawn : 
 " The quantity of air to be warmed per minute in habitable 
 rooms and public buildings, must be three and a half cubic feet 
 for each person the room contains, and one and a quarter cubic 
 feet for each square foot of glass. For conservatories, forcing- 
 houses, and other buildings of this description, the quantity 
 of air to be warmed per minute must be one and a quarter 
 cubic feet for each square foot of glass which the building 
 contains. When the quantity of air required to be heated 
 has been thus ascertained, the length of pipe which will be 
 necessary to heat the building, may be found by the following 
 rule : multiply 125 (the excess of temperature of the pipe 
 above that of the surrounding air) by the difference between 
 the temperature at which the room is purposed to be kept 
 when at its maximum, and the temperature of the external 
 air; and divide this product by the difference between the 
 temperature of the pipes and the proposed temperature of the 
 room ; then, the quotient thus obtained, when multiplied by 
 the number of cubic feet of air to be warmed per minute, and 
 this product divided by 222 (the number of cubic feet of air 
 raised 1 per minute by one foot of 4-inch pipe) will give 
 the number of feet in length of pipe four inches diameter, 
 which will produce the desired effect." 
 
 When 3-inch pipes are used, the quantity of pipe required 
 to produce the same effect will, of course, be different. To 
 obtain it, the number of feet of 4-inch pipe obtained by the 
 above rule must be multiplied by 1.33. If 2-inch pipe be 
 used, the quantity of 4 -inch pipe must be multiplied by two. 
 
 If we wish to determine the quantity of pipe required to 
 maintain a constant temperature of 75 in a hot-house, we 
 must suppose the external air occasionally to fall as low as 
 10, and calculate from this temperature. The amount of 
 heat to be supplied by the pipes is obviously that which is 
 expended by the glass, the cooling power of which is exactly 
 proportioned to the difference between the internal and the 
 
FORM OF THE BOILER. 
 
 external temperature, the actual cubical contents of the house 
 making no difference in the result. If such a house have 800 
 square feet of glass, it can easily be calculated from the preced- 
 ing data, that this quantity will cool down 1,000 cubic feet of 
 air per minute from 75 to 10, which will require 292 feet of 
 4-inch pipe. If the maximum temperature of the pipe be 
 200, and the water be at 40 before lighting the fire, the 
 maximum temperature will be attained in about four hours 
 and a half ; with 3-inch pipe in about three hours and a quar- 
 ter ; and with 2-inch pipe in about two hours and a quarter ; 
 depending, however, upon the structure of the furnace, and 
 the quantity of coal consumed. If the external temperature 
 be higher than 10, the effect will be produced in a proportion- 
 ally shorter time. 
 
 In churches and large public rooms, with an average 
 number of doors and windows, and moderate ventilation, a 
 more simple rule will apply for ascertaining the quantity of 
 pipe required. Where a number of persons are assembled, a 
 large amount of heat is generated by respiration, so that a 
 very moderate artificial temperature is sufficient to prevent the 
 sensation of cold. In such a case, the air does not require to 
 be heated above 55 or 58, and the rule is to take the cubical 
 measurement of the space to be heated, and dividing this 
 by 200, the quotient will be the number of feet of '4-inch pipe 
 required. 
 
 The efficiency of any form of hot water apparatus will, of 
 course, greatly depend on the boiler, which ought to be so 
 constructed as to expose the largest amount of surface to the 
 fire in the smallest space ; to absorb the heat from the fuel, 
 so that as little as possible may escape up the chimney ; to 
 allow free circulation of the water throughout its entire ex- 
 tent, and not be liable to get out of order by constant use. 
 A variety of boilers are figured in Mr. Hood's work, and their 
 respective merits considered on scientific grounds. One of 
 these boilers is shewn in Fig. 56. It is of cast iron, and the 
 part exposed to the fire is covered with a series of ribs two 
 
146 THE BOILER AND THE FURNACE. 
 
 inches deep, and about one-fourth or 
 three-eighths of an inch thick, radiating 
 from the crown of the arch at an aver- 
 age distance of two inches from each 
 other. These ribs greatly increase the 
 
 surface exposed to the fire, exactly where the effect is greatest ; 
 for being immediately over the burning fuel, it receives the 
 whole of the heat radiated by the fire. The form of this 
 boiler being hemispherical, will also expose the largest amount 
 of surface within a given area. The boiler shewn in Fig. 54, 
 being of wrought iron, and, therefore, thinner than cast iron, 
 absorbs the greatest amount of heat from the fuel. 
 
 With respect to the size of the boiler, it has been shewn 
 by experiment that four square feet of surface in an iron boiler 
 will evaporate one cubic foot of water per hour when exposed 
 to the direct action of a tolerably strong fire. The same ex- 
 tent of heating surface which will evaporate one cubic foot of 
 water per hour from the temperature of 52, will be sufficient 
 to supply the requisite amount of heat to 232 feet of 4-inch 
 pipe, the temperature of which is required to be kept 140 
 above the surrounding air ; or one square foot of boiler sur- 
 face exposed to the direct action of the fire, or three square 
 feet of flue surface, will supply the necessary heat to about 58 
 superficial feet of pipe, or, in round numbers, one foot of boiler 
 to 50 feet of pipe. But as this is the maximum effect, a 
 somewhat larger allowance ought in general to be made. If 
 the difference of temperature be 120 instead of 140, the 
 same surface of boiler will supply the requisite amount of heat 
 to one-sixth more pipe, and if the difference be only 100, the 
 same boiler will supply above one-third more pipe than the 
 quantity stated. 
 
 With respect to the furnace, the rate of combustion of the 
 fuel will depend chiefly on the size of the furnace-bars, pro- 
 vided the furnace door be double and fit tightly. The ash-pit 
 should also be provided with a door to exclude the excess of 
 air when the fire is required to burn slowly. A dumb-plate 
 
THE PIPES AND THE WATER. 147 
 
 should also be provided, to cause the combustion to be most 
 active at the hinder part of the furnace instead of directly 
 under the boiler. The fuel will thus be gradually coked, the 
 smoke consumed, and the fuel economised. 
 
 In an apparatus containing 600 feet of 4-inch pipe, the 
 area of the furnace-bars should be 300 square inches, so that 
 14 inches in width and 22 inches in length will give the 
 amount of surface required. To obtain the greatest heat in 
 the shortest time, the area of the bars should be proportion- 
 ally increased, so that a larger fire may be obtained. The 
 fire ought at all times to be kept thin and bright, and to 
 obtain a good effect from the fuel, one pound weight of coal 
 ought to raise 391bs. of water from 32 to 212.* 
 
 The best kind of pipes for hot water apparatus are those 
 with socket-joints ; flange-joints having long been out of use 
 for this purpose. Where the socket-joints are well made, there 
 is no fear of leakage, for the pipes themselves will yield before 
 the joints will give way, or before the faucet end of one pipe 
 can be drawn out of the socket of the other. The joints 
 must be well caulked with spun yarn, and filled up with 
 iron cement, or with a cement made of quicklime and lin- 
 seed oil. 
 
 Soft or rain-water ought always to be used in the hot 
 water apparatus, because, if hard water be used, its salts will 
 form a sediment or crust in the boiler, and interfere with its 
 action. But as there is very little evaporation from this kind 
 of apparatus, the boiler will not require cleaning out for years, 
 if a moderate degree of attention be bestowed on the water 
 employed. 
 
 When the apparatus is not in use, care must be taken to 
 prevent the water from freezing in the pipes, or the sudden 
 expansive force of the water in freezing may crack them. If 
 
 * In the Cornish engines 65j, and even 851bs. of water have been 
 raised from 32 to 212, by the combustion of one pound of coal. This 
 is a far more favourable result than has been produced with any other 
 boilers or qualities of coal, than those employed in the experiment. 
 
 H 2 
 
148 THE HIGH PRESSURE APPARATUS. 
 
 the apparatus is not likely to be used for some time during 
 winter, it is better to empty the pipes than incur the risk of 
 freezing. It has been proposed to fill the pipes with oil in- 
 stead of water, and as the boiling point of oil is nearly three 
 times higher than that of water, it was thought that a tem- 
 perature of 400 might be safely given to the pipes. It was 
 found, however, that the oil at high temperatures became thick 
 and viscid, and at length changed into a gelatinous mass, com- 
 pletely stopping all circulation in the pipes. 
 
 In the forms of apparatus to which the preceding details 
 refer, the temperature of the water never rises to the ordinary 
 boiling point (212) ; but we have now to notice a method, in 
 which the temperature of the water is often beyond 300 ; 
 this is the high-pressure method contrived by Mr. Perkins.* 
 In its simplest form, the apparatus consists of a continuous or 
 endless pipe, closed in all parts, and filled with water. There 
 is no boiler to this apparatus, its place being supplied by 
 coiling up a portion of the pipe (generally one-sixth of the 
 whole length) and arranging this in the furnace. The remain- 
 ing five-sixths of the pipe are heated by the circulation of the 
 hot water, which flows from the top of the coil, and cooling in 
 its progress through the building, returns to the bottom of the 
 coil to be re-heated. The diameter of the pipe is one inch exter- 
 nally, and half an inch internally, and is formed of wrought iron. 
 The coil in the furnace being entirely surrounded by the fire, 
 the water is quickly heated, and becoming also filled with in- 
 numerable bubbles of steam, these impart a great specific 
 levity to the ascending current. At the upper part of the 
 pipe, the steam bubbles condense into water, and uniting 
 with the column in the return pipe, which is comparatively 
 cool, the descent is rapid in proportion to the expansion of 
 the water in the ascending column, or, in other words, ac- 
 
 * One authority on this subject, is Mr. Eichardson's Treatise on the 
 Warming and Ventilation of Buildings, showing the advantages of the 
 Improved System of Heated Water Circulation, &c. Second Edition. 
 London, 1839. 
 
THE EXPANSION PIPE THE FURNACE. 149 
 
 cording to the relative specific gravities of the two columns of 
 water. 
 
 As the expansive force of water is almost irresistible, in 
 consequence of its extremely limited elasticity, it is necessary 
 in the high pressure apparatus to make some provision for the 
 expansion of the water when heated. The necessity for this 
 will appear from the fact, that water heated from 39.45 (the 
 point of greatest condensation) to 212, expands about -$ part 
 of its bulk ; and the force exerted on the pipes by this ex- 
 pansion, would be equal to 14, 12 libs, on the square inch. 
 The method adopted, is to connect a large pipe, called the ex- 
 pansion pipe, 21 inches diameter, with some part of the appa- 
 ratus, either horizontally or vertically. It should be placed 
 at the highest point of the apparatus, and at the bottom of 
 the expansion pipe is inserted the filling pipe through which 
 the apparatus is filled. While the apparatus is being filled 
 with water, the expansion tube is left open at the top j water is 
 then poured in through the filling tube, and as it rises in the 
 pipes, drives out the air before it. When the pipes are full, 
 the filling pipe and the expansion tube are carefully closed 
 with screw plugs. It is important to expel all the air from 
 the pipes, and this is done, in the first instance, by pumping 
 the water repeatedly through them. The expansion pipe 
 is, of course, left empiy, as its use is to allow the water 
 in the pipes to expand on being heated, and thus pre- 
 vent the danger of bursting. From 15 to 20 per cent, of ex- 
 pansion space is generally allowed in practice. 
 
 The furnace is generally so arranged in the building re- 
 quired to be heated, as to allow the tube proceeding from the 
 top of the coil to be carried straight up at once to the highest 
 level at which the water has to circulate j here the expansion 
 tube is situated, and from this point, two or more descending 
 columns can be formed, which, after circulating through 
 different and distant parts of the building, unite at length in 
 one pipe, just before entering the bottom of the coil in the 
 furnace. 
 
150 
 
 AEBANGEMENT OF THE PIPES. 
 
 The whole arrangement will be better understood by refer- 
 
 ring to Fig. 57, in which a is 
 the ascending column ; 6, the 
 expansion tube j c, the de- 
 scending columns; and d, 
 the coil in the furnace. 
 
 The heat is communicated 
 to the air of the rooms from 
 the external surface of the 
 pipes, which are coiled up as 
 at e e, and placed within 
 pedestals, ranged about the 
 1 room with open trellis work 
 in front, or they may be sunk 
 in stone floors, placed behind 
 skirtings, or in the fire places 
 of each floor, the flues being 
 stopped, or arranged in any 
 other convenient manner. 
 
 In consequence of the great 
 internal pressure, which these 
 tubes have to sustain, con- 
 siderable care is required in 
 HE their manufacture. They are 
 made of the best wrought 
 iron, rolled into sheets a 
 quarter of an inch thick, and 
 of the proper width. The 
 edges are then brought nearly 
 together, the whole length of 
 the iron, which is generally 
 
 turning off the about 12 feet. In this state it 
 
 toil* when, desired. 
 
 heated to a welding heat. 
 One end is then grasped by an instrument firmly attached to 
 an endless chain, revolving by steam power, and a man applies 
 
METHOD OF JOINING THE PIPES. 151 
 
 a pair of circular nippers, which, when closed, press the tube 
 into the required size, and which he holds firmly while the 
 tube is drawn through them by the engine. The edges are 
 thus brought into perfect contact, and are so completely 
 welded after passing two or three times through the nip- 
 pers, that a conical piece of iron driven into the end of 
 the tube will not open it at the joint sooner than at any other 
 
 When the tubes are screwed together at each end, they 
 are proved by hydrostatic pressure, with a force equal to 
 3,0001bs. on the square inch of internal surface. In this state 
 they are sent to London, and such is the purity and ductility 
 of the iron, that the tubes can be easily bent, while cold, into 
 coils of different sizes and shapes, as required. 
 
 When the tubes are properly arranged and fixed in the 
 building, the whole apparatus is filled with water by a force 
 pump, and subjected to considerable pressure, before light- 
 ing the fire. In this way, faulty pipes or leaky joints are 
 detected. 
 
 The tubes are joined by placing the ends within a socket, 
 forming a right and left hand screw, the edge of one tube 
 having been flattened^ and the other sharpened : they are then 
 58. screwed so tightly together, that the 
 
 sharpened edge of one pipe is in- 
 dented in the flattened surface of the 
 other. Another method of connect- 
 ing the pipes is by a cone joint. A 
 double cone of iron is inserted into the ends of the pipes 
 to be joined, and is made tight by two screw bolts, as 
 shewn in Fig. 58. This joint is quickly made, and is very 
 strong. 
 
 The furnace varies in form and dimensions according to cir- 
 cumstances ; but a very common arrangement is shewn in 
 Fig. 59. The size is about three and a half feet square, in- 
 creasing to six feet, according to the extent of pipe connected 
 with it. The fire occupies a small space in the centre, raised 
 
152 
 
 ARRANGEMENT OF THE FURNACE. 
 
 Fig. 59. 
 
 about one foot 
 from the ground, 
 and the fuel is 
 supplied through 
 the hopper door, 
 m, at the top. The 
 outer casing, a, 
 is of common 
 brick-work; b b, 
 are Welsh fire- 
 lumps ; c c, are 
 fire-bricks, sup- 
 porting the coil, 
 k ; d d, reservoirs 
 for the dust and 
 soot, which would 
 otherwise clog the coil j #, bearing bars for the grate ; k, the 
 grate : the fire-door is double, and there are also doors to 
 Fig. eo. the ash-pit and dust reservoirs. 
 
 Fig. 60 shews the descending tube 
 entering the fire-chamber, and 
 passing through the bearing bars, 
 g g, of the grate, h. Fig. 61 is a 
 section of the back well or reservoir, d d, formed so as to sup- 
 port the coil, and to cause the soot and dust to fall to the bottom. 
 In this arrangement of the furnace, the ignited coal is sur- 
 rounded on three sides by a thickness of nine-inch fire-brick, 
 or Welsh lumps; the hopper door is also placed in one 
 of these lumps ; the coil is contained 
 in a chamber round the fire-brick, four 
 and a half inches wide ; the pipe enters 
 this chamber, passing through the bear- 
 ing bars of the grate, which tends to 
 preserve the grate from burning ; the 
 pipe passes out from the top of the 
 coil, at the upper part of the chamber. 
 
 Fig. 61. 
 
APPARATUS IN THE BRITISH MUSEUM. 153 
 
 The smoke passes through the chamber containing the pipes, 
 and escapes through an opening at the back. The coil is in 
 actual contact with the fire only in front. The best fuel for 
 this furnace is coke or Welsh hard coal, such as is not liable 
 to clog. The furnace may be placed in a cellar, or be com- 
 pletely removed from the building to be warmed. The heat 
 of the furnace can be moderated by closing the ash-pit door, 
 and opening the furnace door, or the reservoir doors, so as to 
 lessen the draught and admit cold air to the coil. 
 
 In the apparatus erected at the British Museum for warm- 
 ing the print-room and the bird-room, the furnace is in a vault 
 in the basement story, and the pipes, entering a flue, are 
 carried up about forty feet to two pedestals, one in each room ; 
 one containing 360 feet of pipe, and the other 400 feet. About 
 140 feet of pipe are employed in the flow and return pipes in 
 the flue, and 150 feet are coiled up in the furnace. In this way, 
 1,050 feet of pipe are employed : the apparatus is very powerful, 
 and supplies the requisite amount of heat. The print-room is 
 about 40 feet long, by 30 feet wide, and the ceiling contains 
 large sky-lights. The temperature of 65 can easily be main- 
 tained in this room during winter. The fire is lighted at 6, 
 A.M., and is allowed to burn briskly till sufficient heat is pro- 
 duced in the rooms, when the damper in the flue is partially 
 closed. A slow fire is thus maintained : at 11, A.M., a fresh 
 supply of fuel is added, and this supports the fire till 4, P.M., 
 when all the fires at the Museum are extinguished.* 
 
 The above details will suffice to show the nature and appli- 
 cation of this apparatus. For its adaptation to houses and 
 public buildings, under a greater variety of circumstances, we 
 must refer to Mr. Richardson's work. We fully agree with 
 him, that in any building where this apparatus is intended to 
 
 * Mr. Hood states, on the contrary, that, owing to the smallness of 
 the pipes in the high-pressure apparatus, the coil cools so rapidly when 
 the fire slackens in intensity, that the heat of the building is materially 
 affected by the least alteration in the force of the fire, instead of main- 
 taining that permanence of temperature which is so peculiarly the 
 characteristic of the hot- water apparatus with large pipes. 
 
 H5 
 
154 SAFETY OF THE APPARATUS. 
 
 be erected, it ought not to be introduced as an after-thought. 
 " It should be remembered, that as its complete success, and 
 its economical character, depend, in a great measure, upon due 
 consideration of its benefits being given at the commencement 
 of a building, so it ought, in future, to engage the primary 
 consideration of the architect and builder." 
 
 It is, however, of great importance, to ascertain whether 
 this apparatus is perfectly safe, for even a doubt on the subject 
 must be fatal to its general introduction. The average tem- 
 perature of the pipes is stated to be generally about 350 ; but 
 a very material difference in temperature, amounting sometimes 
 to 200 or 300, is said to occur in different parts of the appa- 
 ratus, in consequence of the great resistance which the water 
 meets with in the numerous bends and angles of this small 
 pipe. The temperature of the coil will, of course, give the 
 working effect of the apparatus, but the temperature of any 
 part of the pipe will furnish data for estimating its safety ; for 
 whatever is the temperature, and, consequently, the pressure 
 in the coil, must be the pressure on any other part of the 
 apparatus ; for by the law of equal pressures of fluids, an in- 
 creased pressure at one part will generate an equally increased 
 pressure at every other part of the system. 
 
 A very elegant method of ascertaining the temperature of a 
 heated surface of iron or steel, consists in filing it bright, and 
 then noting the colour of the thin film of oxide which forms 
 thereon.* Mr. Hood states, that in some apparatus, if that 
 part of the pipe which is immediately above the furnace be 
 filed bright, the iron will become of a straw colour, showing 
 a temperature of about 450. In other instances, it will be- 
 
 * Steel becomes a very faint yellow .... at .. 430 Fahr. 
 
 pale straw colour .... . . 450 
 
 Ml yellow ....... 470 
 
 brown ....... 490 
 
 brown, with purple spots . . . 510 
 
 purple ....... 630 
 
 blue ....... 550 
 
 full blue ....... 560 
 
 dark blue, verging on black . . 600 
 
AMOUNT OF INTERNAL PRESSURE. 155 
 
 come purple =about 530, and, in some cases, of a full blue 
 colour=560. Now, as there is always steam in some part of 
 the apparatus, the pressure can be calculated from the tempe- 
 rature, and a temperature of 450= a pressure of 4201bs. on 
 the square inch; 530=9001bs. ; and 560=l,150lbs. per 
 square inch. 
 
 Although these pipes are proved, at a pressure of nearly 
 3,0001bs. per square inch, and the force required to break a 
 wrought iron pipe of one inch external, and half an inch inter- 
 nal diameter, requires 8,8221bs. per square inch on the internal 
 diameter, yet these calculations are taken for the cold metal. 
 By exposing iron to long continued heat, it loses its fibrous 
 texture, and acquires a crystalline character, whereby its tena- 
 city and cohesive strength are greatly weakened. 
 
 In order to make this apparatus safe, Mr. Hood suggests 
 that, instead of hermetically sealing the expansion-pipe, it 
 should be furnished with a valve, so contrived, as to press with 
 a weight of 1351bs. on the square inch. This would prevent 
 the temperature from rising above 350 in any part : the 
 pressure would then be nine atmospheres, which is a limit more 
 than sufficient for any working apparatus where safety is of 
 importance. 
 
 But, supposing the apparatus were to burst in any part, the 
 effects would, by no means, resemble those which accompany 
 the explosion of a steam boiler. One of the pipes would, pro- 
 bably, crack, and the water, under high pressure, escaping in 
 a jet, a portion of it would be instantly converted into steam, 
 while that which remained as water would sink to 212. This 
 would have the effect of scalding water under ordinary circum- 
 stances, but the high pressure steam would not scald, because 
 its capacity for latent heat is greatly increased by its rapid 
 expansion, on being suddenly liberated, so that instead of 
 imparting heat, it abstracts heat from surrounding objects. 
 The only real danger that would be likely to ensue, would be 
 from the jet of hot water, and this must, in any case, be of 
 trifling amount. 
 
PAET II. 
 
 CHAPTEK I. 
 
 ON THE GENERAL PRINCIPLES OF VENTILATION j AND THE 
 METHOD OP VENTILATING BUILDINGS, SHIPS, ETC., BY SPON- 
 TANEOUS ACTION, AND BY MECHANICAL CONTRIVANCES. 
 
 REAUMUR remarks, " Ce que la Nature apprend est 3911 de 
 bonne heure," and as Nature is the best, as well as the earliest, 
 teacher, we take our first example, in the history of ventilation, 
 from the lower animals, and, we venture to assert, that a more 
 difficult, or, apparently, more hopeless problem, does not exist 
 in our rooms and crowded assemblies, our mines and ships, 
 than in the case about to be proposed. 
 
 Imagine a dome- shaped building, perfectly air-tight, except 
 through a small hole at the bottom, capable of containing 
 thirty or forty thousand animals, full of life and activity ; 
 every portion of the enclosed space that can be spared being 
 filled with curious machinery ; the problem is, how to warm 
 and ventilate such a space, so as to maintain a proper tempe- 
 rature, and yet to give to every individual within it a proper 
 supply of air. 
 
 Now this is the condition of a common bee-hive, and we 
 may remark, that if, with all our machines, and contrivances, 
 and scientific resources, the combined operation of warming 
 and ventilating a room be difficult or unsatisfactory, how in- 
 finitely more so must be that of a small bee-hive, crowded with 
 bees, the greater part of the interior filled up with combs of 
 waxen cells, and only one small opening for the ingress and 
 
VENTILATION OP THE BEE-HIVE. 157 
 
 egress of the inhabitants, or for the escape of foul air and the 
 entrance of fresh. 
 
 In a common hive, there is absolutely no other door or 
 window, or opening, than this small entrance hole ; for, on 
 taking possession of a new hive, the bees stop up all the cracks 
 and chinks, with a resinous substance named propolis, for the 
 purpose of keeping out insect depredators; and the proprietor, 
 with the same object, generally plasters the hive to the stool, 
 and, in order to keep off the rain, covers it with a heavy straw 
 cap, or turns a large pan over it. 
 
 It must not be supposed that, because the vitality of insects 
 is greater than that of warm-blooded animals, bees are not 
 affected by the same agencies which affect us, for they are so, 
 and in a similar manner : they fall down apparently dead, if 
 confined in a close vessel ; they perish in gases which destroy 
 us ; they perspire and faint with too much heat ; and are 
 frozen to death by exposure to too much cold. 
 
 Huber introduced some bees into the receiver of an air- 
 pump. They bore a considerable rarefaction of the air with- 
 out any apparent injury ; on carrying it further, they fell 
 down motionless, but revived on exposure to the air. In 
 another experiment, three glass vessels, of the capacity of six- 
 teen fluid ounces, were taken ; 250 worker bees were intro- 
 duced into one, the same number into another, and 150 males 
 into the third. The first and the third were shut close, and 
 the second was partially closed. In a quarter of an hour, the 
 workers in the close vessel became uneasy ; they breathed 
 with difficulty, perspired copiously, and licked the moisture 
 from the sides of the vessel. In another quarter of an hour, 
 they fell down apparently dead. They revived, however, on 
 exposure to the air. The males were affected more fatally, 
 for none survived ; but the bees in the vessel which admitted 
 air, did not suffer. On examining the air in the two close 
 vessels, the oxygen was found to have disappeared, and wa$ 
 replaced by carbonic acid : other bees, introduced into it, 
 
158 RESPIRATION OP BEES. 
 
 perished immediately. On adding a small portion of oxygen 
 gas to it, other hees lived in it ; but they became insensible 
 instantly on being plunged into carbonic acid, and revived on 
 exposure to the air : they perished irrecoverably in nitrogen 
 and hydrogen gases. Similar experiments, performed with 
 the eggs, the larvae, and the nymphs of bees, proved the con- 
 version of oxygen into carbonic acid, in all three states. The 
 larvae consumed more oxygen than the eggs, and less than the 
 nymphs. Eggs, put into foul air, lost their vitality. Larvse 
 resisted the pernicious influence of carbonic acid better than 
 the perfect insect would have done, but the nymphs died 
 almost instantly therein. 
 
 These, and many other analogous experiments, prove that 
 the respiration of bees has a similar vitiating effect upon a 
 confined atmosphere, as the respiration of larger animals, and 
 that bees require constant supplies of fresh air, in the same 
 manner as other living creatures. They also require their 
 dwelling to be kept moderately cool. When from any cir- 
 stance, such as exposure to the sun, overcrowding, or the 
 excitement produced by fear, anger, or preparation for swarm- 
 ing, the temperature of the hive is greatly raised, the bees 
 evidently suffer. They often perspire so copiously, as to 
 be drenched with moisture ; and on fine summer nights, 
 thousands of them may be seen hanging out in festoons 
 and clusters, for the purpose of relieving the crowded state of 
 the hive. 
 
 On inquiring into the method adopted by the bees for 
 renewing the air of the hive, Huber was struck by the constant 
 appearance of a number of the workers arranged on each side 
 of the entrance hole, a little within the hive, incessantly en- 
 gaged in vibrating their wings. In order to see what effect 
 a similar fanning would produce on the air of a glass receiver, 
 containing a lighted taper, M. Senebier advised him to construct 
 a little artificial ventilator, consisting of eighteen tin vanes. 
 This was put into a box, on the top of which was adapted a large 
 
VENTILATION OF THE HIVE. 159 
 
 cylindrical vessel, of the capacity of up wards of 3,000 cubic inches. 
 A lighted taper, contained in this vessel, was extinguished in 
 eight minutes ; but, on restoring the air, and setting the ven- 
 tilator in motion, the taper burnt brilliantly, and continued to 
 do so as long as the vanes were kept moving. On holding 
 small pieces of paper, suspended by threads, before the aper- 
 ture, the existence of two currents of air became evident ; 
 there was a current of hot air rushing out, and, at the same 
 time, a current of cold air passing in. On holding little bits 
 of paper or cotton near the hole of the hive, a similar effect 
 was produced : they were impelled towards the entrance by 
 the in-going current, and when they encountered the out-going 
 current, they were repelled with equal rapidity. 
 
 These two currents are established in the hive, by the fan- 
 ning motion of the bees' wings. The worker bees perform 
 the office of ventilators, and the number, at one time, varies 
 from eight or ten to twenty or thirty, according to the state 
 of the hive and the heat of the weather. We have frequently 
 watched their proceedings with interest. They station them- 
 selves in files, just within the entrance of the hive, with their 
 heads towards the entrance, while another and a larger party 
 stand a considerable way within the hive, with their heads 
 also towards the entrance. They plant their feet as firmly as 
 possible on the floor of the hive, stretching forward the first 
 pair of legs, extending the second pair to the right and left, 
 while the third, being placed near together, are kept perpen- 
 dicular to the abdomen, so as to give that part a considerable 
 elevation ; then uniting the two wings of each side by meanis 
 of the small marginal hooks with which they are provided, so 
 as to make them present as large a surface as possible to the 
 air, they vibrate them with such rapidity, that they become 
 almost invisible. The two sets of ventilators, standing with 
 their heads opposed to each other, thus produce a complete 
 circulation of the air of the hive, and keep down the tempera- 
 ture to that point which is fitted to the nature of the animal. 
 When a higher temperature is required at one particular spot, 
 
160 WARMING AND VENTILATION 
 
 as, for example, on the combs containing the young brood, the 
 nurse bees place themselves over the cells, and by increas- 
 ing the rapidity of their respirations, produce a large 
 amount of animal heat just where it is wanted. The car- 
 bonic acid, and other products of respiration, are got rid of by 
 ventilation. 
 
 The laborious task of ventilating the hive is seldom or never 
 intermitted in the common form of hive, either by day or by 
 night, during summer. There are separate gangs of venti- 
 lators, each gang being on duty for about half an hour. In 
 winter, when the bees are quiet, and their respiration only 
 just sufficient to maintain vitality, the ventilating process is 
 not carried on ; but by gently tapping on the hive, its inmates 
 wake up, increase the number of their respirations, and, con- 
 sequently, the temperature of the hive, to such a degree, that 
 the air becomes intolerably hot and vitiated. To remedy this, 
 a number of worker bees go to the entrance of the hive, and 
 begin to ventilate the interior as laboriously as in summer, 
 although the open air be too cold for them to venture 
 out. 
 
 Bearing in mind the details given in the introduction 
 and the conclusion arrived at, (page 11), that the animal frame 
 is a true apparatus for combustion, we can understand how 
 bees regulate the temperature of their hive : when greater 
 heat is wanted, they increase the rapidity of their respirations, 
 or, in other words, they burn more carbon ; but they get rid 
 of the products of combustion, and also prevent the heat from 
 accumulating, by the process of ventilation. Bees, in general, 
 maintain a temperature of 10 or 15 above that of the exter- 
 nal air ; but, at certain periods, this temperature is greatly 
 increased. Mr. Newport observed, in the month of June, 
 when the atmosphere was at 56 or 58, that the temperature 
 of the hive was 96 or 98. This high temperature arose from 
 the nurse bees incubating on the combs, and voluntarily in- 
 creasing their heat by means of increased respiration. In 
 winter, on the contrary, when only just sufficient heat is 
 
OF THE BEE-HIVE. 161 
 
 required to maintain vitality, less carbon is burnt, and the 
 temperature of the hive is accordingly low. In one observa- 
 tion by Mr. Newport at 7.15, A.M., on the 2nd January, 1836, 
 when there was a clear intense frost, and the thermometer in 
 the open air stood a little above 17, a thermometer perma- 
 nently fixed in the hive, marked a temperature of 30, or two 
 degrees below the freezing point. The bees were roused by 
 tapping on the hive, and in the course of sixteen minutes, the 
 thermometer rose to 70, or 53 above the temperature of the 
 external air. On another occasion, when the temperature of 
 the hive had been raised to about 70, the external air being 
 at 40, the bees soon cooled it down to 57 by their mode of 
 ventilation, and kept it at that point as long as the hive con- 
 tinued to be excited. 
 
 By this process of ventilation also, bees get rid of noxious 
 odours in the hive. Huber found that, on introducing into 
 the hive some penetrating vapour, disagreeable to the bees, 
 they always increased the amount of ventilation, until they got 
 rid of it. Humble-bees adopt the same method of dispelling 
 pernicious odours; but it is remarkable, that neither their 
 males, nor those of domestic bees, seem capable of using their 
 wings as ventilators. " Ventilation is, therefore," says Huber, 
 " one of the industrial operations peculiar to the workers. The 
 Author of Nature, in assigning a dwelling to those insects 
 where the air can hardly penetrate, bestows the means of 
 averting the fatal effects which might result from the vitiation 
 of their atmosphere. Perhaps the bee is the only creature 
 entrusted with so important a function, and which indicates 
 such delicacy in its organization." 
 
 The circumstances under which our rooms are placed, are 
 far more favourable to ventilation than the bee-hive. Whether 
 the ventilation be left to chance, or whether any special appa- 
 ratus be erected for the purpose, the foul vitiated air must 
 be got rid of, and fresh air, adapted to the purposes of respi- 
 ration, admitted in sufficient quantity, that is, at the rate of 
 about four cubic feet per minute for each individual in the 
 
162 FORCE OF VENTILATION. 
 
 room. The air must leave the room at certain openings, 
 or be drawn out of it thereby at this rate, while a similar 
 amount of fresh air must enter to supply the loss, or, to speak 
 more accurately, the force or impetus of the incoming air 
 ought slightly to compress the air of the room, and assist the 
 efflux of the vitiated air, and this, in its turn, ought to be so 
 heated, as to have a certain amount of ascentional force over 
 that of the incoming air. In some cases, mechanical means 
 are necessary to expel the air, such as fanners, bellows, pumps, 
 &c., but it is generally more convenient, as well as economical, 
 to trust to the natural method of getting rid of the vitiated 
 air, by making certain ventilating tubes or openings at the 
 highest point of the room towards which the hot air tends to 
 flow.* 
 
 The same cause which produces the draught of common 
 chimneys, and of the glass chimneys of our oil and gas lamps 
 will, if circumstances be favourable, set in motion and dis- 
 charge the vitiated air of our rooms, at the same time that it 
 brings in the fresh. For example, the air of a common chim- 
 ney, under the influence of the fire, expands according to a 
 law applicable to all gases, namely, -j-J^ of its volume for each 
 degree of Fahrenheit's scale from 32 to 212. Now if a 
 chimney or ventilating flue were ten feet high, and the tem- 
 perature of the column of air within it were raised 20 above 
 the temperature of the external air, the expansion would 
 be ^Vths, or -^th of its bulk. This would so far diminish 
 the specific gravity of the heated column, that it would require 
 10^ feet thereof to balance a column of the external air of 
 
 * It may be as well to mention, that some writers have divided arti- 
 ficial ventilation into two branches, which they call plenum and vacuum. 
 By the first, air is forced, by mechanical contrivances, into the interior 
 of a building, and the vitiated air is allowed to escape by openings 
 contrived for the purpose ; by the second, the vitiated air is drawn out 
 of the building by means of mechanical contrivances, or through the 
 agency of heat artificially excited, and the fresh air thus finds an en- 
 trance through channels adapted to the purpose. 
 
VELOCITY OF EFFLUX. 163 
 
 10 feet. It has been already stated (page 83), that the velocity 
 of efflux is equal to the velocity of a heavy body falling through 
 the difference in height between the two columns ; and in the 
 case before us, the difference of five inches is equal to 5.174 
 feet per second, or 310 feet per minute ; and this is the 
 velocity with which a heated column of air would be forced 
 through the ventilating tube or chimney ; and supposing the 
 dimensions of this to be one foot square, then 310 cubic feet of 
 air would escape per minute. This, however, is the theoretical 
 amount, which does not take into account the retarding effects 
 of friction arising from the roughness of the tube, or any 
 angles or bends in it, or the increased density of the hot air 
 from the presence of carbon from the fuel, in a minutely 
 divided state. In practice, it is usual to allow from ^th to 4rd 
 for the effects of friction. 
 
 As the velocity of a falling body, in a second of time, is 
 known to be eight times the square root of the height of the 
 descent, in decimals of a foot, so the velocity of discharge per 
 second, through vent tubes or chimneys, may be briefly stated 
 as equal to eight times the square root of the difference in 
 height of the two columns of air, in decimals of a foot. 
 This number, reduced one-fourth for friction, and the re- 
 mainder multiplied by 60, will give the true velocity of 
 efflux per minute; and the area of the tube, in feet, 
 or decimals of a foot, multiplied by this last number, 
 will give the number of cubic feet of air discharged pel- 
 minute. 
 
 In estimating the total height of a column of heated air, we 
 must calculate the total vertical height from the floor of the 
 room to be ventilated to the top of the tube, where it dis- 
 charges into the open air. All horizontal bends and angles 
 may be neglected, for these make no difference in the vertical 
 height, but only increase the amount of friction, and deprive 
 the heated column of a portion of its ascentional force, by 
 cooling. As the vertical height of the column gives the velo- 
 city of discharge in the ratio of the square root of the height 
 
164 'ARRANGEMENT OF VENT TUBES. 
 
 of the column, it is necessary, where several vent tubes be em- 
 ployed, that they all be of the same vertical height, or the 
 highest vent will prevent the efficient action of the lower ones, 
 so that there may actually be a smaller discharge through two 
 tubes than through one only. 
 
 So also, when several openings are made above the level of 
 the floor of a room, the highest may be the only one capable 
 of acting as an abduction tube, the other lower openings 
 often serving as induction tubes, discharging cold air into the 
 room instead of taking it out, and, in doing so, lower the 
 temperature of the hot vitiated air, and prevent it from 
 escaping; thus not only causing the bad air to be breathed 
 over again, but filling the room with unpleasant draughts. 
 But if the highest abduction tube be too small to carry 
 off the requisite quantity of hot air, the tube next below it 
 in elevation at any part of the room will act as an abduction 
 tube. 
 
 If the lower openings for the admission of cool fresh air 
 be too small in proportion to those for the escape of the hot 
 air, a current of cold air will descend through one part of the 
 hot air tube, and the hot air will ascend through another part 
 of the same tube, an effect which we have already seen takes 
 place in the ventilation of a bee-hive. This effect may also 
 be shewn by a very pleasing experiment. Place a lighted 
 taper in a flat dish, and cover it with a glass receiver, fur- 
 nished with a long glass chimney placed immediately over the 
 flame. If the bottom of the receiver does not come into very 
 close contact with the dish, enough air will enter to support 
 combustion, and the draught or current of hot air will escape 
 up the chimney, and the taper will continue to burn for any 
 length of time. If we now shift the receiver a little on one 
 side, so that the flame may not be immediately under the 
 chimney, the products of combustion will impinge upon the 
 glass, and cooling down and mingling with the air of the re- 
 ceiver, will contaminate it so much, that the taper imme- 
 diately begins to burn dimly, and will soon be extinguished. 
 
EXPERIMENTAL ILLUSTRATIONS. 
 
 165 
 
 On bringing the chimney over the flame, it will speedily im- 
 prove in appearance ; the smoke and other products of com- 
 bustion will be rapidly discharged, and the receiver will be- 
 come bright and transparent as before. But suppose we cut 
 off all communication with the external air from below by 
 pouring a little water into the dish, so as to cover the mouth 
 of the receiver, we shall then have the case of a room which 
 is provided with a vent tube near the ceiling, but has no pro- 
 vision for admitting fresh air from any lower openings ; in 
 such case, the fresh air will seek to enter by the ventilating 
 tube. If this be large enough, the outgoing hot air and the 
 incoming cool air will divide the tube into two parts. But if, 
 as in the experiment before us, the 
 ventilating tube or chimney be too 
 narrow, the hot and cold currents will 
 interfere with each other; the ten- 
 dency of the hot air to rise and of the 
 cold air to descend, will prevent the 
 escape of the one and the entrance of 
 the other, and the taper will soon be 
 extinguished for want of fresh air. 
 But if the chimney be divided into 
 two portions by a flat strip of tin 
 plate passed down it, as in Fig. 62, 
 and the taper be lighted and placed 
 in its former position, it will continue 
 to burn for any length of time; for, by 
 this arrangement, the two currents of 
 hot and cold air are prevented from interfering with each 
 other ; the hot air will pass up one channel and escape, and 
 the cold air will descend the other channel to feed the flame. 
 By holding a piece of smoking paper or the glowing wick of 
 a taper on one side of the chimney, the smoke will be drawn 
 down, thereby indicating the descending current of cool air ; 
 while, on the other side, the smoke will be driven up by the 
 ascending current of heated air. 
 
166 VENTILATION AT DIFFERENT SEASONS. 
 
 In the same manner these counter currents may be fre- 
 quently noticed in churches and other crowded places, where 
 due provision is seldom made for the entrance of fresh air, and 
 the escape of the foul. It is usual in summer to mitigate the 
 effects of the hot vitiated atmosphere, by throwing open the 
 windows. A portion of the foul air, it is true, escapes by 
 these channels, but a counter current immediately sets in 
 through each of them, exposing the persons near them to the 
 dangerous effects of draught, and also cooling the foul air 
 which is seeking to escape, and sending it down to be breathed 
 over again. 
 
 Now, in order that these open windows or any other ven- 
 tilating openings be effective, it is necessary that the lower 
 openings for the admission of fresh air be as numerous, or, at 
 least, as large as the upper ones, and larger if possible. By 
 making these lower openings, or induction pipes, or doors, or 
 valves, or any other contrivances both numerous and capacious, 
 the entering current is broken up and divided, and cold 
 draughts are avoided. This remark is equally applicable to 
 fresh air, which has been previously warmed by any artificial 
 process ; for, by admitting it into the room through numerous 
 channels, it distributes its warmth more equally, and does not 
 rise to the ceiling too rapidly. 
 
 Ventilation is more difficult in summer than in winter, be- 
 cause, in warm weather, the difference between the internal and 
 the external temperature is much less than in cold weather. 
 In all cases of spontaneous ventilation, it will, therefore, be ne- 
 cessary in summer to increase the number or the size of the 
 ventilating tubes. When these tubes are constructed, their 
 number and size ought to be adapted to the full amount 
 of summer ventilation. In winter, some of them can be 
 closed, and others, if too large, ought to admit of being re- 
 duced in size.* 
 
 * Perforated zinc is now getting into use as a ventilator. The pane 
 of glass furthest from the fire-place and in the upper row is taken out, 
 
FORM OF THE CEILING. 167 
 
 Tredgold, in his work on Warming and Ventilating (Second 
 edition. London, 1836), has given some very sensible direc- 
 tions for the ventilation of a church, which, of course, apply 
 equally to any other public building, and, to a certain extent, 
 to private houses. He advises, that the spaces for the admis- 
 sion of cold air be abundantly large, and divided as much as 
 possible j they should be in or near the floor (see Fig. 65), so 
 that the air may not have to descend upon any one; by 
 making the openings large, and covering them on the inside 
 with rather close wire work (sixty-four apertures to the square 
 inch) most of the current may be prevented ; and it may be 
 still further prevented by bringing tubes under the paving to 
 admit fresh air into the central parts of the church. Of 
 course these openings must be provided with shutters, so as 
 to close them when desirable. Provision should be made for 
 the escape of the warm air at different parts of the ceiling, 
 through air-trunks furnished with registers. The form of the 
 mouth of the vent tube, is a circular aperture, with a 
 balanced circular register plate, p (Fig. 64), to close it. 
 This plate should be larger than the aperture, in order 
 that the air may be drawn into a horizontal current, for 
 the purpose of taking away the portion of air next the 
 ceiling. If the tube were left without a plate, the air im- 
 mediately under it would press forward up the tube, and 
 very little of the worst air which collects at the ceiling 
 would escape. 
 
 A flat or level ceiling is not well adapted to the purposes of 
 ventilation j but a still worse form of ceiling is that which is 
 divided into coffers, for in these the air collects, gets cooled, 
 and descends. For effective ventilation, ceilings ought always 
 to be dome-shaped, coved, arched, groined, or of the form of a 
 truncated pyramid, as shewn in Fig. 63, so as to rise in the 
 
 and its place supplied with a sheet of zinc, having 220 perforations to 
 the square inch. Panes of perforated glass are also abundantly supplied, 
 as well as glass louvres. 
 
168 
 
 VENTILATION THROUGH THE CEILING. 
 
 Fig. 63. centre, and at the 
 
 centre or most ele- 
 vated point, the 
 ventilating tube, T, 
 should be placed. 
 When curved lines 
 are not used, ceil- 
 ings of this form 
 ought always to be 
 adopted; they are not much more expensive than flat 
 ones ; they have a better effect, and are vastly superior as 
 far as ventilation is concerned, supposing an opening be made 
 in the central or highest point for the escape of the vitiated 
 air. 
 
 As it is not always possible to conduct the vent tube at once 
 in a vertical line from the highest point of the ceiling, there is 
 no objection to giving it a horizontal direction for some dis- 
 tance. In Fig. 64, the vent tube, A B, is horizontal, and is 
 
 Fig. 64. 
 
 conducted between the timbers of a floor. This figure also 
 shews how the timbers may be disposed, so that there may 
 be a rise in the centre without loss of space.* c is a cord 
 passing over a pulley, D, for raising or lowering the register 
 plate, p. This plate is balanced by a weight attached to the 
 
 * In Tredgold's figure, the timbers on each side of the ventilating 
 opening, D, are made to dip, as shewn in the dotted line at t, (Fig. 64). 
 This ought always, if possible, to be avoided, as it prevents the free 
 passage of the air ; and even such a slight impediment as this might 
 cause a stratum of air near the ceiling to cool and descend before it had 
 time to escape up the opening. 
 
 
VENTILATION OF CHURCHES. 169 
 
 lower part of the cord, which passes down nearly to the floor 
 of the room, where it is secured by a hook. 
 
 Where the vent tubes can be carried up vertically from the 
 ceiling to the top of the building, it is always better to do so, 
 because the friction of the hot ascending current is thereby 
 diminished. If the vent be made through the ceiling of a 
 church into the space in the roof, and from this space, an air 
 tube be taken up within the steeple or bell-turret, an effectual 
 ventilation may be obtained without adding outlets to the 
 roof. Where external appearance is less regarded, a common 
 louvre-boarded top, for an outlet from the roof, will answer. 
 All side and end windows should be kept closed ; for if the 
 apertures at the ceiling be of the proper size, and due pro- 
 vision be made for supplying fresh air, these open windows, 
 as already .explained, will diminish, not increase the amount of 
 ventilation. The reason has been already stated why ventila* 
 tion is difficult to maintain in warm weather. Of course, it 
 becomes especially so in very calm, warm weather. Mr. Tred- 
 gold gives a case of this kind : Suppose we wish to provide 
 ventilation sufficient to prevent the internal air from being of 
 a higher temperature than 5 above that of the external air. 
 Now, if the external air be at 70, we shall not be able to keep 
 the internal temperature down to 75 with a less escape of air 
 than 2| cubic feet per minute for each person ; because each 
 person will heat, at least, that quantity of air 5 in a minute, 
 at these temperatures. When a church contains 1,000 per- 
 sons, and the height from the floor to the top of the tube is 
 49 feet, the sum of the apertures that will allow 2,500 cubic 
 feet of air per minute to escape, when the excess of tempera- 
 ture is 5, must be equal to 12 square feet. If the height be 
 only 36 feet, the size of the aperture must be 14 square feet 
 nearly. When the ceiling is level, this area should be divided 
 among five or more ventilators, disposed in different parts of 
 the ceiling ; but in a vaulted or arched roof, three are recom- 
 mended to be placed in the highest part of the ceiling, as at D, 
 in Fig. 64. 
 
 i 
 
170 
 
 VENTILATION OF CHURCHES. 
 
 It is also recommended, that the openings for admitting 
 cold air be about double the area of those at the ceiling. The 
 air should not be taken from very near the ground, nor from 
 a confined place. In designing and constructing a new 
 building, flues might be made for the special purpose of 
 supplying the interior with fresh air. Each flue might open 
 in the cornice, pass down between the piers, and under the 
 flooring of the church or other building, and terminate in 
 apertures which would be covered with gratings. By disposing 
 some of these flues on each side of the church, they would act 
 with the wind in any direction. These exterior openings 
 should, however, be covered with a grating, to prevent birds 
 from building in them, and thus stopping them up. The 
 accompanying sketch (Fig. 65), from a design by Mr. Garbett 
 will shew at a glance the arrangements required for the proper 
 
 Fig. 65. 
 
EXAMPLE FROM THE ALHAMBRA. 
 
 171 
 
 ventilation of a church ; but before the desirable objects of 
 properly warming and ventilating churches and other public 
 buildings are fully attained, it will be necessary for architects 
 to combine a profound knowledge of their art, with a good 
 acquaintance with chemical and physical science. 
 
 In some of the old buildings, which still excite the admira- 
 tion of persons of cultivated taste, by the beauty of their 
 arrangements and architectural details, we sometimes meet 
 with special provision for ventilation, arranged on the truest 
 principles. Thus, in the " Hall of the Baths" in the Alham- 
 bra, at Granada, the roof is perforated with ventilating 
 
 Fig. 
 
 openings, and is not only of the best possible form for 
 the purpose of ventilation, but the openings themselves 
 are of the best possible shape, being wider at the lower 
 extremity than at the upper ; and in order that these openings 
 may present the least possible amount of friction to the 
 outgoing air, they are provided with short tubes of baked 
 earth, covered, with a green vitreous glazing. This beautiful 
 roof is shewn in Fig. 66, and two of the elegant ventilating 
 tubes are shewn separately on a larger scale in Fig. 67. 
 
 i 2 
 
172 ABNOTT'S METHOD OF 
 
 rig. 67. Such are the methods by which churches 
 
 and other public buildings may be spontane- 
 ously ventilated. In the rooms of private 
 houses, the ventilation must also be sponta- 
 neous, for if the slightest trouble be entailed 
 on the inmates, even to the opening of a 
 window, it will be neglected. The means for 
 ventilation must be cheap, easily procurable, 
 always in place, self-acting, not liable to 
 get out of order, requiring no adjustment, no 
 care whatever on the part of the inmates. It would seem im- 
 possible, at first view, to contrive anything at all likely to an- 
 swer these conditions, and yet the thing has been done in the 
 most perfect manner by that truly patriotic individual, Dr. 
 Arnott, so well known for his water-bed, his stove, and other 
 inventions, which he has freely presented to the public, without 
 seeking or desiring any emolument to himself. 
 
 In the autumn of 1849, when the cholera was raging in 
 London and in the towns of the United Kingdom, the Board 
 of Health recommended, in one of their notifications pub- 
 lished in the London Gazette, that in every badly ventilated 
 dwelling "considerable and immediate relief may be given 
 by a plan suggested by Dr. Arnott, of taking a brick out 
 of the wall near the ceiling of the room, so as to open a 
 direct communication between the room and the chimney. 
 Any occasional temporary inconvenience of down-draught will 
 be more than compensated by the beneficial results of this 
 simple ventilating process." 
 
 A few days after this authoritative recommendation of this 
 contrivance, and in consequence of numerous applications for 
 further information on the subject, Dr. Arnott addressed a letter 
 to the Times newspaper, dated 22nd September, 1849. This 
 admirable letter is so interesting and so pertinent to the sub- 
 ject of this little Rudimentary Treatise, that we venture to 
 transfer nearly the whole of it to our pages : 
 
 "I assume," says Dr. Arnott, "that most of your readers 
 
VENTILATING ROOMS, ETC. 173 
 
 already understand, or will now learn, that the air which we 
 breathe, and which is used to stuff air-pillows, consists of ma- 
 terial elements as much as the water which we drink or the 
 food which we eat, indeed, consists altogether of oxygen and 
 nitrogen; the first of which forms also seven-eighths by 
 weight of the substance of water, and the other nearly one- 
 fifth by weight of the substance of flesh j and that there is 
 surrounding our globe, to a depth of about fifty miles, a light 
 fluid ocean of such air, called the atmosphere, into which, near 
 the surface of the earth, certain impurities are always rising 
 from the functions of animal and vegetable life, and the de- 
 composition of substances in putrefaction, combustion, &c., 
 just as into the sea and great rivers some impurities are always 
 entering from the sewers all which impurities, however, are 
 quickly so diluted or dissipated in the great masses, as to 
 become absolutely imperceptible, and eventually, by the admi- 
 rable processes of nature, are decomposed and changed, so 
 that the great oceans of air and water retain ever their state 
 of perfection. I assume further, that your readers know that 
 fresh air for breathing is the most immediately urgent of the 
 essentials to life, as proved by the instant death of any one 
 totally deprived of it through drowning or strangulation ; and 
 by the slower death of men compelled to breathe over again 
 the same small quantity of air, as when lately seventy-three 
 passengers were suffocated in an Irish steam-boat, of which 
 the hold was shut up for an hour by closely covered hatches ; 
 and by the still slower death, accompanied generally by some 
 induced form of chronic disease, of persons condemned to 
 breathe habitually impure air, like the dwellers in crowded ill- 
 ventilated rooms and foul neighbourhoods ; and, lastly, as 
 proved by the fact, that pestilence or infectious diseases are 
 engendered or propagated almost only where impurities in the 
 air are known to abound, and particularly where the poison of 
 the human breath and other emanations from living bodies are 
 allowed to mingle in considerable quantity as instanced in 
 the gaol and ship fevers, which so lately, as in the days of the 
 
174 ARNOTT'S METHOD OF 
 
 philanthropist Howard, carried off a large proportion of those 
 who entered gaols and ships ; and, as instanced in that fearful 
 disease, which, at the Black Assizes at Oxford, in July, 1577, 
 spread from the prisoners to the Court, and within two days 
 had killed the judge, the sheriff, seyeral justices of the peace, 
 most of the jury, and a great mass of the audience, and 
 which afterwards spread among the people of the town. 
 This was a fever which did its work as quickly as the cholera 
 does now. 
 
 "Assuming that these points are tolerably understood, I 
 shall proceed to shew, that from faults in the construction and 
 management of our houses, many persons are unconsciously 
 doing, in regard to the air they breathe, nearly as fishes would 
 be doing in regard to the water they breathe, if, instead of the 
 pure element of the yast rivers or boundless sea streaming 
 past them, they shut themselves up in holes near the shores 
 filled with water defiled by their own bodies, and from other 
 foul sources. And I shall have to shew, that the spread of 
 cholera in this country has been much influenced by the gross 
 oversights referred to. 
 
 " All the valued reports and published opinions on cholera 
 go far to prove, that in this climate, at least, any foreign mor- 
 bific agent or influence which produces it, comes comparatively 
 harmless to persons of vigorous health, and to those who are 
 living in favourable circumstances ; but that if it find persons 
 with the vital powers much depressed or disturbed from any 
 cause, and even for a short time, as happens from intemper- 
 ance, from improper food or drink, from great fatigue or 
 anxiety, but, above all, from want of fresh air, and, conse- 
 quently, from breathing that which is foul, it readily over- 
 comes them. It would seem as if the peculiar morbid agent 
 could as little, by itself, produce the fatal disease, as one 
 of the two elements concerned in a common gas explosion, 
 namely, the coal gas and the atmospheric air, can alone pro- 
 duce the explosion. The great unanimity among writers and 
 speakers on the subject, in regarding foul atmosphere as the 
 
VENTILATING ROOMS, ETC. 175 
 
 chief vehicle or favourer, if not a chief efficient cause of the 
 pestilence, is seen in the fact, of how familiar to the common 
 ear have lately become the words and phrases " malaria, filth 
 crowded dwellings, crowded neighbourhoods, close rooms, 
 faulty sewers, drains, and cesspools, or total want of these, 
 effluvia of graveyards," &c., all of which are merely so many 
 names for foul air, and for sources from which it may arise. 
 Singularly, however, little attention has yet been given from 
 authority to the chief source of poisonous air and to means of 
 ventilation by which all kinds of foul air may certainly be 
 removed. 
 
 " A system of draining and cleansing, water-supply and 
 flushing, for instance, to the obtainment of which, chiefly, the 
 Board of Health has hitherto devoted its attention, can, how- 
 ever good, influence only that quantity and kind of aerial 
 impurity which arises from retained solid or liquid filth within 
 or about a house, but it leaves absolutely untouched the other 
 and really more important kind, which, in known quantity, is 
 never absent where men are breathing, namely, the filth and 
 poison of the human breath. This latter kind evidently plays 
 the most important part in all cases of a crowd, and, therefore, 
 such catastrophes as that of the Tooting school, with 1,100 
 children, of whom nearly 300 were seized by cholera, of the 
 House of Refuge for the Destitute, and of the two great 
 crowded lunatic asylums here, where the disease made similar 
 havoc, for places so public as these, and visited daily by 
 numerous strangers, could not be allowed to remain visibly 
 impure with solid and liquid filth, like the Rookery of St. 
 Giles's, and other such localities. Now, good ventilation, which, 
 although few persons comparatively are as yet aware of the 
 fact, is easily to be had, not only entirely dissipates and ren- 
 ders absolutely inert the breath-poison of inmates, however 
 numerous, and even of fever patients ; but in doing this, it 
 necessarily at the same time carries away at once all the first- 
 named kinds of poison, arising from bad drains, or want of 
 drains, and thus acts as a most important substitute for good 
 
176 ARNOTT'S METHOD OP 
 
 draining, until there be time to plan, and safe opportunity to 
 establish such. It is further to be noted, that it is chiefly 
 when the poison of drains, &c., is caught and retained under 
 cover, and is there mixed with the breath, that it becomes 
 very active, for scavengers, nightmen, and gravediggers, who 
 work in the open air, are not often assailed with disease ; and 
 in foul neighbourhoods, persons like butchers, who live in open 
 shops, or policemen, who walk generally in the open streets, 
 or in Paris, the people who manufacture a great part of the 
 town filth into portable manure, suffer very little. 
 
 " To illustrate the efficacy of ventilation or dilution with 
 fresh air, in rendering quite harmless any aerial poison, I may 
 adduce the explanation given in a report of mine on fevers, 
 furnished at the request of the Poor Law Commissioners in 
 1840, of the fact, that the malaria or infection of marsh fevers, 
 such as occur in the Pontine marshes near Rome, and of all 
 the deadly tropical fevers, affects persons almost only in the 
 night. Yet the malaria or poison from decomposing organic 
 matters which causes these fevers, is formed during the day 
 under the influence of the hot sun still more abundantly than 
 during the colder night ; but in the day, the direct beams of 
 the sun warm the surface of the earth so intensely, that any 
 air touching that surface is similarly heated, and rises away 
 like a fire balloon, carrying up with it, of course, and much 
 diluting, all poisonous malaria formed there. During the 
 night, on the contrary, the surface of the earth no longer re- 
 ceiving the sun's rays, soon radiates away its heat, so that a 
 thermometer lying on the ground is found to be several de- 
 grees colder than one hanging in the air a few feet above. The 
 poison formed near the ground, therefore, at night, instead of 
 being heated and lifted, and quickly dissipated, as during the 
 day, is rendered cold and comparatively dense, and lies on the 
 earth a concentrated mass, which it may be death to inspire. 
 Hence, the value in such situations of sleeping apartments 
 near the top of a house, or of apartments below, which shut 
 out the night air, and are large enough to contain a sufficient 
 
VENTILATING ROOMS, ETC. 177 
 
 supply of the purer day air for the persons using them at night, 
 and of mechanical means of taking down pure air from above 
 the house to be a supply during the night. At a certain 
 height above the surface of the earth, the atmosphere being 
 nearly of equal purity all the earth over, a man rising in a 
 balloon, or obtaining air for his house, from a certain eleva- 
 tion might be considered to have changed his country, any 
 peculiarity of the atmosphere below, owing to the great dilu- 
 tion effected before it reached the height, becoming absolutely 
 insensible. 
 
 " Now, in regard to the dilution of aerial poisons in houses 
 by ventilation, I have to explain, that every chimney in a 
 house is what is called a sucking or drawing air-pump, of a 
 certain force, and can easily be rendered a valuable ventilating 
 pump. A chimney is a pump first, by reason of the suction 
 or approach to a vacuum made at the open top of any tube 
 across which the wind blows directly ; and, secondly, because 
 the flue is usually occupied, even when there is no fire, by air 
 somewhat warmer than the external air, and has, therefore, 
 even in a calm day, what is called a chimney draught propor- 
 tioned to the difference. In England, therefore, of old, when 
 the chimney breast was always made higher than the heads of 
 persons sitting or sleeping in rooms, a room with an open 
 chimney was tolerably well ventilated in the lower part, where 
 the inmates breathed. The modern fashion, however, of very 
 low grates and low chimney openings, has changed the case 
 completely, for such openings can draw air only from the bot- 
 tom of the rooms, where generally the coolest, the last entered, 
 and therefore the purest air, is found, while the hotter air of 
 the breath, of lights, of warm food, and often of subterranean 
 drains, &c., rises and stagnates near the ceilings, and gradually 
 corrupts there. Such heated, impure air, no more tends down- 
 wards again to escape or dive under the chimney-piece, than 
 oil in an inverted bottle immersed in water will dive down 
 through the water to escape by the bottle's mouth ; and such 
 a bottle or other vessel containing oil, and so placed in water 
 
 tiff 
 
178 ARNOTT'S METHOD OF 
 
 with its open mouth downwards, even if left in a running 
 stream, would retain the oil for any length of time. If, how- 
 ever, an opening be made into a chimney flue through the wall 
 near the ceiling of the room, then will all the hot impure air 
 of the room as certainly pass away by that opening, as oil from 
 the inverted bottle would instantly all escape upwards through 
 a small opening made near the elevated bottom of the bottle. 
 A top window-sash, lowered a little, instead of serving, as 
 many people believe it does, like such an opening into the 
 chimney flue, becomes generally, in obedience to the chimney 
 draught, merely an inlet of cold air, which first falls as a cas- 
 cade to the floor, and then glides towards the chimney, and 
 gradually passes away by this, leaving the hotter impure air 
 of the room nearly untouched. 
 
 " For years past, I have recommended the adoption of such 
 ventilating chimney openings as above described, and I de- 
 vised a balanced metallic valve, to prevent, during the use of 
 fires, the escape of smoke to the room. The advantages of 
 these openings and valves were soon so manifest, that the 
 referees appointed under the Building Act added a clause to 
 their bill allowing the introduction of the valves, and directing 
 how they were to be placed, and they are now in very extensive 
 use. A good illustration of the subject was afforded in St. 
 James's parish, where some quarters are densely inhabited by 
 the families of Irish labourers. These localities formerly sent 
 an enormous number of sick to the neighbouring dispensary. 
 Mr. Toynbee, the able medical chief of that dispensary, came 
 to consult me respecting the ventilation of such places, and, 
 on my recommendation, had openings made into the chimney 
 flues of the rooms near the ceilings, by removing a single 
 brick, and placing there a piece of wire gauze, with a light 
 curtain flap hanging against the inside, to prevent the issue of 
 smoke in gusty weather. The decided effect produced at 
 once on the feelings of the inmates was so remarkable, that 
 there was an extensive demand for the new appliance, and, as 
 a consequence of its adoption, Mr. Toynbee had soon to report, 
 
VENTILATING ROOMS, ETC. 179 
 
 in evidence given before the Health of Towns Commission, 
 and in other published documents, both an extraordinary 
 reduction of the number of sick applying for relief, and of the 
 severity of diseases occurring.* Wide experience elsewhere 
 has since obtained similar results. Most of the hospitals and 
 poor-houses in the kingdom now have these chimney-valves ; 
 and most of the medical men and others who have published 
 of late on sanitary matters, have strongly commended them. 
 Had the present Board of Health possessed the power, and 
 deemed the means expedient, the chimney openings might, as 
 a prevention of cholera, almost in one day, and at the expense 
 of about a shilling for a poor man's room, have been established 
 over the whole kingdom. 
 
 " Mr. Simpson, the registrar of deaths for St. Giles's parish, 
 an experienced practitioner, whose judgment I value much, 
 related to me lately, that he had been called to visit a house 
 in one of the crowded courts, to register the death of an in- 
 mate from cholera. He found five other persons living in 
 the room, which was most close and offensive. He advised 
 the immediate removal of all to other lodgings. A second 
 died before the removal took place, and soon after,, in the 
 poor-house and elsewhere, three others died who had breathed 
 the foul air of that room. Mr. Simpson expressed to me his 
 belief that if there had been the opening described above 
 into the chimney near the ceiling, this horrid history would 
 not have been to tell. I believe so too, and I believe that 
 there have been in London lately very many similar cases." 
 
 * We are truly thankful to be able to state, that in two parishes in 
 London St. George's and St. James's a society has been established 
 for the purpose of supplying the sick poor with clothing, food, and 
 means for ventilating their apartments. The Honorary Secretary to 
 this society is Joseph Toynbee, Esq., 60, King Street, Golden Square, 
 who has volunteered to give the necessary information to any District 
 Visiting Society desirous of extending their usefulness by ventilating 
 the dwellings of the poor. We trust that Mr. Toynbee's benevolence 
 will be rewarded by extensive success. 
 
180 
 
 THE EGYPTIAN WIND-CONDUCTOR. 
 
 Fig, 68. 
 
 Among other modes of spontaneous ventilation, may be 
 mentioned the mulguf, or wind conductor, of the ancient 
 Egyptians, and still in use in modern Egypt. It was erected at 
 
 the top of the house, 
 as in Fig. 68, and 
 consisted of a frame 
 covered or enclosed 
 on all sides, except 
 at the mouths, which 
 were open in the 
 direction of the pre- 
 vailing winds. The 
 roof of the mulguf 
 sloped down from 
 each open end to 
 the centre, where a 
 partition divided it, 
 and deflected the 
 wind down into the 
 apartments below. Mr. Wilkinson, in his work on Egypt, 
 gives a view of part of Cairo, shewing the mulgufs on the 
 houses of the modern Egyptians. The ancient mulgufs were 
 double, as shewn in the figure, but the modern ones are single, 
 and the opening is in the direction of the prevailing north- 
 west wind. They consist of strong frame-work, to which 
 several planks of wood are nailed, according to the breadth 
 and length proposed ; and, if required of cheaper materials, 
 reeds or mats, covered with stucco, are used instead of planks. 
 This contrivance acts on a similar principle to the wind-sail 
 used on board ships, which consists of a sail spread out to the 
 wind : from the lower part proceeds a cylinder of canvas dis- 
 tended by hoops, which maybe carried down through the hatches, 
 to any deck or hold where fresh air is required. Its action 
 depends on the force of the wind, and the mode of arranging 
 it : it is of no use in calm weather, when ventilation is often 
 most needed : and it is equally unavailable in stormy weather, 
 
THE WIND-SAIL AND THE FAN. 181 
 
 when the hatches are battened down, and the mencrowded below. 
 Indeed, unless some contrivance could be made for getting rid 
 of the vitiated air by other openings, the supply of fresh air by 
 the wind-sail must always be partial and defective. 
 
 The next class of mechanical contrivances for ventilation, is 
 that in which the aid of an attendant is required, either to 
 maintain the ventilating machine in motion, or to superintend 
 the mechanical power that does so. The simplest of these 
 contrivances is the fan, which has been used from time imme- 
 morial, especially in warm climates, where it is often made of 
 an enormous size, and being wielded by an attendant with 
 the dexterity acquired by long practice, its effect is very power- 
 ful in giving motion to the air, and producing the sensation 
 of coolness, by bringing a larger supply to the person, and 
 abstracting the heat by its motion. The punkah, as commonly 
 used in India, is nothing more than a gigantic fan, suspended 
 in the centre of the apartment, above a bed or table. Attached 
 to one side is a line, which passes out of the apartment through 
 the wall to an attendant on the outside, who thus gives motion 
 to the large extended surface within, and thus prevents the 
 air from stagnating. Some years ago, a steam-engine was 
 sent from England to move the punkahs in the palace of the 
 Nabob of Oude. A machine, called the zephyr, was proposed 
 some years ago by Mr. Dobson, for giving motion to the air of 
 a room. Two sails or punkahs, crossing each other at right 
 angles, were mounted on a frame, and a rotatory motion was 
 given thereto, by suspending it from a case containing a 
 mechanism like that of a bottle-jack. This case was suspended 
 by lines passing over pullies in the ceiling, and balanced by 
 weights, so that the sails could be made to play at any eleva- 
 tion, In all these contrivances, motion is given to the air, 
 but the rooms containing them are not ventilated thereby ; 
 the vitiated air is whirled and whisked about, but not driven 
 out, and its place supplied by fresh air. 
 
 This objection does not apply to the fanning-wheel or blower, 
 now ,so commonly used for ventilating factories and other 
 
182 
 
 DESAGULIERS FAN 
 
 Fig. 69. 
 
 places where a steam-engine is constantly at work, to supply 
 the required moving power. The fanner was invented by 
 Dr. Desaguliers, in 1734. Its object was stated to be for 
 "changing the air of the room of sick people in a little 
 time, either by drawing out the foul air, or forcing in fresh 
 air, or doing both successively, without opening doors or win- 
 dows." This, it was supposed, would be of very great use in all 
 hospitals and prisons, and would also serve to convey air into 
 a distant room, " nay, to perfume it occasionally." The wheel 
 was 7 feet in diameter, and 1 foot wide, and had twelve radii 
 
 or partitions, (Fig. 69), ap- 
 proaching within 9 inches of 
 the axis, leaving a circular 
 opening 1, 2, 3, 4, 18 inches 
 in diameter. This wheel was 
 enclosed in a concentric case, 
 (Fig. 71), furnished with a 
 blowing pipe, B, on the upper 
 part and a suction pipe, s 
 (Fig. 70), communicating at 
 a, with the central opening 
 in the wheel, which was turned by 
 a handle, attached to the axis, A, 
 which passed through the case, and 
 rested on a standard, E. The fanner 
 was made so as to revolve easily, but 
 as closely to the concentric casing 
 as possible, without any communication 
 with the air, except through the suction 
 and blowing pipes. To ensure this, a 
 ring of blanket ting was fixed within the 
 case, g g, and a similar ring at H H, so 
 that the edges of the vanes being in con- 
 tact therewith, the air would have no other escape than by the 
 blowing pipe, B. By the revolution of the wheel, the air within 
 the case was rapidly impelled by centrifugal force to the cir- 
 
OB CENTRIFUGAL BLOWER. 183 
 
 Fig. 71 . cumference, where it was condensed, 
 
 whirled round, and forced out, in a 
 powerful current, through the open- 
 ing of the blowing pipe, B, while the 
 partial vacuum thus formed set a 
 current of air in motion towards 
 the centre, which current entering 
 at s, and passing up into a, was 
 distributed between the vanes, and, 
 driven to the circumference, passed out in a powerful continuous 
 blast at B. The suction-pipe, s, could be made to communicate 
 with the external air by means of a pipe, or with a space con- 
 taining heated air, and the blowing pipe could be connected with 
 a room which could thus be filled with cool fresh air, or with 
 warmed air, the quantity being regulated by the speed of the 
 wheel. If foul air had to be drawn out, the suction-pipe was 
 connected with the space containing it, and the blowing-pipe 
 with the external air. 
 
 In the year 1736, a wheel of this description was erected 
 over the ceiling of the House of Commons, for the purpose of 
 drawing out the vitiated air, in the manner just described, a 
 man being kept constantly at work, during the sitting of the 
 house, to turn the wheel. It was stated, that this wheel was 
 " able to suck out the foul air, or throw in fresh, or do both at 
 once, according as the Speaker is pleased to command it, whose 
 order the ventilator waits to receive every day of the session." 
 This apparatus continued to be used for ventilating the House, 
 until the year 1791, when the chief clerk of the House, 
 Mr. Holland, proposed its removal from the room over his own 
 private apartments, to the centre of the roof immediately over 
 the House, as being a more advantageous position. This 
 was accordingly done, and continued in operation until 
 1817, when a similar contrivance was recommended for 
 the ventilation of the House of Lords. It was not, how- 
 ever, erected, for in 1820, the whole business of warm- 
 ing and ventilating both Houses was entrusted to the Marquis 
 
184 DESAGULIERS' FAN 
 
 of Chabannes, whose plan will be noticed in the next 
 chapter. 
 
 But to return to Dr. Desaguliers. About the time when he 
 was engaged in ventilating the House of Commons, the atten- 
 tion of Government was directed to the want of ventilation in 
 our ships, in consequence of the bad health of the troops that 
 were embarked at Spithead to proceed on an expedition 
 against the Spaniards. Numbers were relanded, and sent to 
 the hospital, and the ships are said to have " stunk to such a 
 degree, that they infected one another." " The Lords of the 
 Admiralty applied to Dr. Desaguliers, to shew them the model 
 of his centrifugal wheel and air-pipes ; and after the exhibi- 
 tion, some of them went to see the operation of the wheel 
 fixed over the House of Commons. Sir Jacob Ackworth, the 
 Surveyor of the Navy, attended them, and seemed to approve of 
 the machine as much as they did ; and the Doctor was ordered 
 to make a blowing wheel, with its pipes, to be tried on board 
 the Kinsale at Woolwich, but less than that at the House of 
 Commons, that it might not take up too much room in the 
 ship." Accordingly, the Doctor attended with a small wheel, 
 but Sir Jacob did not condescend to be present. The machine 
 answered admirably : a quantity of pitch and other substances 
 was burnt in the carpenter's room, and the smoke arising 
 therefrom was drawn above deck by a few turns of the wheel. 
 On reversing the valves, air was forced between decks with 
 great energy. Every one present was delighted with the 
 action of this ventilator, and Sir Jacob, hearing of its success, 
 appointed another day for a repetition of the experiment, but 
 requested the Doctor not to attend himself, but to send his 
 carpenter with the apparatus. The particulars of this trial 
 are amusingly told, in a letter from the carpenter, Kembel 
 Whattley, to Dr. Desaguliers. "When Sir Jacob came on 
 board, he was very complaisant to me, and asked me if I was 
 the person that was appointed by Dr. Desaguliers to attend 
 him, in order to try the experiment of the air machine, and I 
 told him I was. Then said he to the men, ' hoist the wind- 
 
OR CENTRIFUGAL BLOWER. 185 
 
 sails ;' and the windsails were hoisted. ' Now,' says he to me, 
 ' we have cut two scuttle-holes at each end of the ship, and 
 you shall see what the windsails will do ; it is our old way 
 when at sea :' and while they were hoisting the sails, I went 
 down under deck to put the engine in order. But I had not 
 been there long, before I was called for. So when I came up 
 it was to see that the wind-sails that were put down would 
 blow out a candle at one of the scuttle-holes. ' Now/ said he, 
 ' I would have you work the engine, and see whether that will 
 throw out so much air as our wind-sails you see do/ ' Lord ! 
 Sir,' said I, ' that, I imagine, was not the intent of the thing ; 
 it was to draw out the foul air from any part of the ship that 
 there were tubes to convey it from. It is impossible that a 
 thing, which is but 3 inches by 5, should throw in as much 
 air as a thing 2 feet 6 inches diameter.' So we talked awhile, 
 and, at last, he told me that he could not stay, but that he 
 had thought so before, and that he was sorry that the machine 
 would not do. ' Pray, Sir,' said I, l let there be a great smoke 
 made in the carpenter's store-room, and see whether the en- 
 gine or your wind-sails will destroy it first.' Then he told 
 me, that he could not possibly stay ; ' but that gentleman 
 there,' said he, pointing to a pretty lusty man that was present, 
 ' shall be with you, and he and you may try the machine as 
 you please ; and I shall think the same of it, from his report, 
 as if I were present.' So, Sir, it was then left to the gentle- 
 man and me to try it ; and I burned pitch in the carpenter's 
 store-room, and made a great smoke, and ordered the engine 
 to be worked, and drew it out in less than five minutes' time. 
 Then I turned the valves, and brought in fresh air j and, as I 
 thought, it gave the gentleman entire satisfaction ; but, how- 
 ever, we made as great a smoke as before, and put down the 
 windsails, and then the smoke was driven into several parts 
 of the ship j and that not in half the time that your engine 
 did it in ; and then it went out above deck. Sir Jacob told 
 me afterwards, that he was sorry that it succeeded no better, 
 but he thought it might be a very pretty thing in a house. 
 Sir Jacob desires his humble service to you." 
 
186 VENTILATION OUGHT TO^BE SPONTANEOUS. 
 
 Dr. Desaguliers complains justly, that "not one of the Lords 
 of the Admiralty, who talked of having many of the ventila- 
 tors made for the preservation of the health of the persons 
 then going to Jamaica, condescended to witness one experi- 
 ment ; and Sir Jacob, who condemned the thing, would not 
 once be present to observe its operation. But thus ended my 
 scheme, which, I hoped, would have been of great benefit to 
 the public." 
 
 The great objection to this plan for ventilating ships, is the 
 necessity of employing men to turn the wheel. The dangers 
 arising from defective ventilation are not of that obvious 
 character which, in many other cases, lead men at once to 
 seek out and apply the remedy. The aerial poison is invisible, 
 and, although chemists and educated persons, who study its 
 nature, are aware of its insidious action in inducing disease, 
 and undermining the health, it is difficult to persuade the 
 multitude, whether of subordinates or of persons in authority, 
 that pure air is as necessary to health and vigour of body, as 
 food, and sleep, and cleanliness. On board a ship, every one has 
 his regular routine duties, the use of which are obvious to those 
 who command as well as to those who perform them, and they 
 are accordingly performed with cheerfulness. But to give the 
 common sailor, in addition to his other duties, the task of 
 turning a wheel for the purpose of pumping out air from 
 between decks, is not likely to be of obvious utility, either to 
 him, or to many of his commanding officers. No system of 
 ventilating apparatus is ever likely to be adapted to the con- 
 ditions of a ship, unless it resemble the excellent system of 
 lightning conductors, invented by Sir W. Snow Harris ; it 
 must be always in its place, ready for use, under all possible 
 circumstances, whether wanted or not. Before Harris's con- 
 ductors were introduced, every ship was furnished with a set 
 of moveable conductors, packed up in a box, to be taken out 
 and applied when wanted. Now the taking out and erecting 
 of these conductors was an extra duty, a special service and 
 was seldom or never performed. A thunder-storm comes on, 
 the ship had not been struck in other storms, why should it 
 
IMPROVED ECCENTRIC FANS. 187 
 
 be struck in this ? and, accordingly, the conductors are left to 
 slumber in the hold. So with any form of ventilating appa- 
 ratus that gives extra trouble to officers or men ; the ship's 
 company have never been suffocated for want of air why 
 should they now 1 Hence all these new-fangled contrivances 
 are dismissed with scorn. 
 
 Very differently circumstanced is the ventilating fan when 
 made a permanent fixture in a factory, and the wheel is con- 
 nected with the force which sets in motion the various ma- 
 chines of the establishment. The ventilator then fulfils all 
 the conditions required. It is always in its place, gives no 
 trouble, does its duty efficiently, and requires no superintend- 
 ence. In speaking of the ventilation of factories, Dr. Ure 
 remarks, that the engineers of Manchester do not, like those 
 of the metropolis, trust for a sufficient supply of fresh air into 
 any crowded hall, to currents physically created in the atmos- 
 phere by the difference of temperature excited by chimney 
 draughts ; but the factory plan is to extract the foul air in 
 measurable volumes, by mechanical means of the simplest and 
 most unfailing kind, especially by eccentric fans, made to 
 revolve with the rapidity of nearly 100 feet per second j and 
 thereby to ensure a constant renewal of the atmosphere in any 
 range of apartments, however large or closely crowded they 
 may be. The effect of one of Fairbairn and Lillie's four- 
 guinea fans upon a large factory is truly admirable ; it not 
 only sweetens the interior space immediately, but renders the 
 ingress of bad odours from without impossible. In a weaving 
 mill, near Manchester, where the ventilation was bad, the 
 proprietor caused a fan apparatus to be mounted. The conse- 
 quence soon became apparent in a curious manner. The 
 work people complained that the ventilator had increased 
 their appetites, and therefore entitled them to a corresponding 
 increase of wages. 
 
 When such a fan, placed at one end of an apartment about 
 200 feet long, is in full action, it throws the air so powerfully 
 out of it, as to create a draught at the other end of the room, 
 
188 
 
 THE IMPROVED FAN. 
 
 capable of keeping a weighted door six inches a-jar. When 
 connected in the attics with a horizontal pipe, into which 
 vertical tunnels from each room are inserted, it draws out the 
 air so rapidly from them, as to cause a breeze from every 
 part of the adjoining floors, thus producing an excess of venti- 
 lation in the apartments. The simple and cheap contrivance 
 of perforated cast-iron boxes, placed on every story in commu- 
 nication with the fan, is the method now in use. A side and 
 a front view of the fan are given in Figs. 72, 73, such as have 
 
 Fig. 72. Fig. 73. 
 
 been used of late years for ventilating factories, for removing 
 through tunnels the dust disengaged in cleaning fibrous 
 materials, such as cotton, hemp, &c., for blowing air into forge 
 fires, and many other similar purposes. It consists of two 
 cast iron end plates, A A, with a central circular opening, c c c, 
 from the circumference of which the outline of each plate 
 enlarges spirally, the point nearest the centre being near d, 
 and that furthest off being under E. This pair of parallel 
 plates is connected by bolts, a a a, a mantle of sheet iron 
 being previously inserted into grooves cast in the edges of the 
 end plates, so as to enclose a cavity with an elongated outlet 
 at B, to which a pipe is attached for carrying off the air in any 
 direction. Within this cavity, a shaft, c, revolves in bearings, 
 b b, placed centrally in the frame-plates, A A. On this shaft, 
 a boss is wedged fast, bearing five flat arms, c c c, to which are 
 rivetted five flat plates or wires of the shapes shewn between 
 
THE IMPROVED FAN. 189 
 
 a and a, in Fig. 73, having a semi- circular piece cut out of 
 them on each side, about the size of the end opening. On 
 one side of the shaft, c, beyond the box-bearing, the fast and 
 loose pulleys, D, are fitted for receiving the driving band, and 
 for turning the wings in the direction shewn by the arrow. 
 Thus the air is driven before them out of the end orifice, B, 
 while it enters by the side openings at c c c. By the centri- 
 fugal force of the revolving wings, the air is condensed towards 
 their extremities, and makes its escape from the pressure 
 through the orifice, B, while it is continually drawn in at the 
 sides by its tendency to restore the equilibrium. The fans 
 are sometimes constructed so as to have their mantles concen- 
 tric with their central shafts, as in Dr. Desaguliers' fan. The 
 improved fan (shewn in Fig. 73), is called the eccentric j the 
 air which escapes through the outlet, B, has undergone com- 
 pression during its whole progress through the spiral space 
 with the revolving wings, and is equal in density to that com- 
 pressed at their extremities by the centrifugal force. The 
 fan, therefore, discharges considerably more air than that with 
 a chamber concentric with its wings (as in Fig. 69), because 
 in the concentric fan, there is considerable loss of power, on 
 account of a large quantity of air being carried round by the 
 leaves of the fan, instead of passing out through the discharge 
 pipe at the circumference \ but in the eccentric fan, each wing 
 or leaf, in passing the point, d, acts as a valve to cut off the 
 entrance of the uncondensed air, which would cause an eddy, 
 and retard the proper current by the inertia of its particles. 
 When the fan is required to draw air out of a series of inde- 
 pendent rooms, it has its circular side openings, c c c, enclosed 
 within caps, which are connected with pipes communicating 
 with such rooms. Slide or throstle valves may be placed in 
 the exhausting, as well as the condensing pipes, for regulating 
 the distribution of the rarefying or blowing power.* 
 
 The fan produces its greatest effect when the extreme points 
 
 * Philosophy of Manufactures. London, 1835. 
 
190 THE AECHIMEDIAN SCEEW. 
 
 of its leaves move through about 80 feet per second. The 
 mean velocity of that portion of the vanes by which the air 
 is discharged, is about seven-eighths of the velocity of the 
 extremities ; but owing to the inertia of the air, there will be 
 a loss in the velocity of the issuing current which will increase 
 with the increased speed of the vanes ; so that, in general, the 
 current will be discharged with a velocity equal to about three- 
 fourths of the velocity of the extremities. This velocity mea- 
 sured in feet per second multiplied by the area of the discharge 
 pipe in square feet, will give the number of cubic feet of air 
 discharged per second. If the effective velocity of the vanes 
 be 70 feet per second, and the sectional area of the discharge 
 tube be three square feet, then 70x3=210 cubic feet of 
 air discharged per second or 12,600 cubic feet per minute. 
 As a cubic foot of air weighs 527 grains, there will be about 
 
 210x60 
 13 cubic feet of air to a pound; therefore j^ = 9691bs. 
 
 weight of air set in motion per minute, with a velocity of 70 
 feet per second. The height from which a heavy body must 
 fall in order to acquire a velocity of 70 feet per second is 76.5 
 feet, which multiplied by the number of pounds weight moved 
 per minute, will give the power necessary to discharge this quan- 
 tity of air at the stated velocity ; and this product divided by 
 38,000 (the number of pounds weight that one horse will 
 raise one foot high per minute) will give the amount of steam- 
 
 76.5X969 
 power required. Therefore oo QAA =2.24 or nearly 2^ 
 
 horses power will be required to discharge the given quantity 
 of air at the velocity stated.* 
 
 The Archimedian screw has lately been proposed as a sub- 
 stitute for the fan in the ventilation of buildings ; but it 
 appears to be in every respect an inferior machine. The 
 only thing that can be said in its favour is, that it is 
 entirely self-acting, requiring no power to set it in motion, 
 
 * Tire, Philosophical Transactions. Hood, Warming and Ven- 
 tilation. 
 
HALES S VENTILATORS. 
 
 191 
 
 except the ascensive force of the vitiated air itself, which 
 acting on the threads or spirals of the screw, causes it to re- 
 volve, and so effects the discharge. This, of course, is an 
 advantage j but as soon as the pressure or condensation of the 
 air between the spirals becomes equal to the friction between 
 the air and the surface of the spirals, no further increase in 
 the amount of discharge takes place. The screw will only 
 discharge small quantities of air at a moderate velocity, and 
 is, therefore, not fitted for ventilation on a large scale. 
 
 Pumps and bellows have also had their share of attention 
 as instruments of ventilation. At the time when Dr. Desa- 
 guliers was endeavouring to get his ventilating fans intro- 
 duced into the navy, Dr. Hales came forward with a rival 
 scheme, which he termed the " Ship's lungs," and he was 
 applied to by Government to fix his apparatus on board the 
 Captain, a seventy gun ship, by way of experiment. A double 
 ventilator of this kind is shewn in Fig. 74. It consisted of two 
 outer cases, B D Q c, each 10 feet long, 4^ feet wide, and 1 3 inches 
 deep inside. The midrif or valve, z, (Fig, 75), was framed of 
 wood, and fixed at one end to each case by iron hinges, and a slip 
 of leather was nailed over the whole length of the joint to make 
 
 Fig. 74. 
 
 it air-tighto This valve moved easily up and down as near the 
 surface of each case as possible. Iron rods, R R, were fixed 
 
192 HALES'S VENTILATOES. 
 
 about six inches from the moveable end of the midrif at N, and 
 were furnished with joints made like two links in a chain, to 
 allow them to preserve a perpendicular position in the motion 
 caused by the rising and falling of the midrifs. The upper ends 
 of these rods were attached to a lever, G F, 12 feet long, moving 
 on a pivot at o, and capable of being worked by two men. 
 The valves marked 1 to 8, each 22 inches long, 6 inches deep, 
 and suspended by copper hinges, were an inch broader and 
 longer than the openings ; and their borders, as well as the 
 corresponding borders of the valve openings, were lined with 
 list or woollen cloth, to deaden their noise when falling. A box 
 Fig. 75. with a large aperture, 
 
 covered the emission 
 valves, from which the 
 air was conveyed by 
 a pipe into the part of 
 the ship that was to be 
 ventilated. Thus, it will 
 
 . 
 struction of this machine 
 
 closely resembles that of the common bellows. The air enters 
 by those valves which are hinged to open inwards, and is 
 emitted at each rise and fall of the midrif through the valves 
 which are hung so as to open outwards into the covering-box, 
 whence it is conveyed through a tube to the parts of the 
 ship requiring ventilation. 
 
 Dr. Hales calculated that his machine would expel a tun 
 of air at each stroke, or six tuns per minute ; and that the 
 air issued from the aperture with a velocity of twenty-five 
 miles an hour. This estimate is far too high, and the machine 
 itself is far inferior to that of his amiable rival, Dr. Desagu- 
 liers ; indeed, the use of the rotatory fan at the present day, 
 and the total practical oblivion of the " Ship's lungs," is a 
 sufficient commentary on the respective merits of the two in- 
 ventions. 
 
 In the experiment in the Captain, Sir Jacob Ackworth 
 
HALES'S VENTILATORS. 193 
 
 condescended to be present, and appears to have behaved to 
 Dr. Hales with civility. It is very probable, that on this 
 occasion, the objection urged against this machine was, that it 
 was not self-acting, but required too constant attention of the 
 seamen to be of any use, for the Doctor, in his treatise, endea- 
 vours to combat such objections in the following terms : " As to 
 the labour and difficulty of working these ventilators, how 
 frivolous and groundless is it when the matter is rightly 
 considered ; for as they are chiefly wanted where there is a 
 great number of men, so the labour of it, equally divided among 
 them, is very inconsiderable ; for if two men can hold to work 
 them for a quarter of an hour, four men, by changing hands, 
 spell and spell, as they term it, may well work for an hour. 
 And suppose there be 500 or 480 men in a ship, and every one 
 takes his share of the work, then, once in five days, it will 
 come to every man's turn to work at it for half an hour. And 
 suppose there be in a transport or Guinea slave ship 200 men, 
 as there is often about that number, then it will come to every 
 man's turn to work the ventilators for half an hour once in 
 forty-eight hours ; but here, as the ventilators will be less than 
 the above described ventilators, so will the labour of working 
 them be also less. This, supposing it necessary to do it in- 
 cessantly night and day, which need not be in a man-of-war 
 when the port-holes can be opened, and there is any degree of 
 wind ; which, suppose it be half the time of the crew's being 
 on ship-board, then it will come to each man's turn but once 
 in ten days. This calculation is made on a supposition, that 
 every individual takes his turn at the ventilator ; but let us 
 allow an abatement of one-fifth for officers, sick, &c., then will 
 the work be no more than half an hour to each man in eight 
 days. But suppose it were to be incessant, can half an hour 
 in five days be thought so hard and great a degree of labour 
 as to render the working of the ventilators an impracticable 
 thing 1 Is not the benefit proposed thereby, viz., the saving 
 yearly of the lives of thousands, a sufficient reward for so small 
 a pittance of labour ? Shall it be said of the brave and un- 
 
 K 
 
194 HALES'S VENTILATORS. 
 
 daunted sailor, that rather than pull his hand out of his 
 bosom, and work for an hour once in ten days, he will choose 
 to lie down and suffer his brave manly spirit to be suffocated 
 in a frowsy stench a stench that has destroyed the lives of 
 millions of the stoutest and bravest, for the lamp of life is 
 sooner thereby quenched than many are aware of."* 
 
 All this argument is perfectly sound, and it must be ad- 
 mitted, that each sailor ought to " work for an hour once in 
 ten days," in order to keep the ship well ventilated. It must 
 also be admitted, that under the old system of lightning con- 
 ductors, the approach of every storm ought to have been a 
 sufficient warning to cause the erection of these safe-guards, in 
 case the ship should be struck. There are many things in life 
 which men ought to do, and much learned and scientific elo- 
 quence is repeatedly urged in favour of their doing them ; but, 
 as indolence, indifference, and ignorance, are not easily moved 
 to exertion, the benefit must, if possible, be conferred without 
 occasioning thought, trouble, or exertion to those who are to 
 share in its advantages. 
 
 Such a contrivance was introduced into English vessels of 
 war, at the very time when the respective merits of Dr. 
 Desaguliers and Dr. Hales' schemes were being discussed. 
 This was Mr. Sutton's air tubes, which will be noticed in the 
 next chapter. These were perfectly successful; but as the 
 plan was made the subject of a patent, and some objection 
 
 * The title of this book is curious, and it promises more than the ma- 
 chines described in it were calculated to perform. It is as follows : " A de- 
 scription of ventilators, whereby great quantities of fresh air may with ease 
 be conveyed into mines, gaols, hospitals, workhouses, and ships, in ex- 
 change for their noxious air. An account also of their great usefulness 
 in many other respects ; as in preserving all sorts of grain dry and sweet, 
 and free from being destroyed by weevils both in granaries and ships, 
 and in preserving many other sorts of goods ; as also in drying corn, 
 malt, hops, gunpowder, &c., and for many other useful purposes. Which 
 was read before the Eoyal Society, in May, 1741. By Stephen Hales, 
 D.D., F.R.S., Eector of Farringdon, Hampshire, and Minister of Ted- 
 dington, Middlesex. London, 1743." 
 
VENTILATION IN SHIPS, ETC. 195 
 
 had been made to the paying for the use of it on board each 
 ship, the scheme seems to have died with the inventor, 
 for we find the complaints of the defective ventilation of ships 
 to be as numerous as ever, and no further improvement appears 
 to have been made until about the gear 1785, when wooden 
 pipes, about nine inches square, were introduced (for which 
 brass tubes were afterwards substituted), running from between 
 decks along the side of the ship, and opening into the air over 
 the gunwale of the forecastle.* The importance of this contriv- 
 ance will be seen, when it is considered, that in frigates the sleep- 
 ing-places of the men are excluded from direct communication 
 with the external air ; and that a number of human beings 
 crowded together in hammocks for hours together, in a small 
 dark confined space, must be highly injurious to health. At- 
 tempts had been made to remedy this by small scuttles cut in 
 the the sides ; but this was frequently objected to, as weaken- 
 ing or endangering the ship. 
 
 One of the most recent additions to our ventilating appa- 
 ratus is Dr. Chowne's patent air-siphon, which acts on a simi- 
 lar principle to that of the smoke consuming stoves, described 
 at page 68, (Fig. 16), and also at pages 105, 107, (Figs. 32 
 and 33.) Fig. 32 was spoken of by Dr. Franklin, " as a 
 kind of inverted siphon ; and as the greater weight of water 
 in the longer leg of a common siphon, in descending, is 
 accompanied by an ascent of the same fluid in the shorter, so 
 in this inverted siphon, the greater quantity of levity of air 
 in the longer leg in rising, is accompanied by the descent of 
 air in the shorter." In the specification of his patent, Dr. 
 Chowne states his invention to consist in the application of a 
 principle which he has found to prevail in the atmosphere, of 
 moving up the longer leg of an inverted siphon, and of enter- 
 ing and descending in the shorter leg, and this without the 
 
 * This contrivance was first pointed out by Dr. Gilbert Blane, in his 
 work On the Diseases Incident to Seamen. London, 1785, and the 
 idea was suggested to him from a similar contrivance in La Nymphe, a 
 French frigate. 
 
 K2 
 
196 CHOWNE'S PATENT 
 
 necessity for the application of artificial heat to the longer 
 leg. " I have found that if a bent tube or hollow passage be 
 fixed with the legs upwards, the legs being of unequal lengths, 
 whether it be in the open air or with the shorter leg commu- 
 nicating with a room or other place, that the air circulates up 
 the longer leg, and it enters and moves down the shorter leg, 
 and that this action is not prevented by making the shorter 
 leg hot whilst the longer leg remains cold, and no artificial 
 heat is necessary to the longer leg of the air -siphon to cause 
 this action to take place ; thus, is the direction of the action 
 of air in a siphon the reverse of that which takes place in a 
 siphon, or like bent passage or tube, when used for water and 
 other liquid, wherein the water or other liquid enters and rises 
 up in the shorter leg, and descends or moves down into the 
 longer leg. And my invention consists of applying this prin- 
 ciple when ventilating rooms or apartments, such as those of a 
 house or ship, or other building or place." 
 
 He then goes on to describe the invention as applied to the 
 rooms of a house where there are chimneys opening into such 
 rooms, and says, in these cases, " I employ the chimney as the 
 longer leg of the air-siphon, which I arrange in order to ven- 
 tilate a room, and I am enabled to use the chimney whether 
 for the time being there is or is not a fire lighted in the fire- 
 place of the room ; but I prefer, when there is no lighted fire, 
 that the fire-place should be closed either by a register stove 
 being shut, if one be used, or, if not, by a close chimney-board, 
 or by other convenient means, and I form a passage or channel 
 either when constructing the building, or by cutting away, if 
 not previously constructed, or I otherwise form such channel 
 or passage, or more than one, from the upper part of the room, 
 or near the ceiling of the room, and cause it to descend and to 
 enter the chimney at a point above the top of the fire-place, 
 when it is an open fire-place, and it may be lower down when 
 closed; and in order that the whole of the upper part of 
 the room may be in communication with such descending 
 passage or channel leading to the chimney, I form a hollow 
 
INVERTED SIPHON. 197 
 
 cornice sufficiently open to allow of the atmosphere at or near 
 the upper part of the room to flow into the same, and owing 
 to the atmospheric siphon which will thus be formed, there 
 will be a constant flow of the air in a direction from the upper 
 part of the room down the descending channel or passage, 
 which will represent the shorter leg, and thence into the 
 chimney, and away up the chimney, which will constitute the 
 longer leg of the air-siphon." 
 
 When fixed gas-burners or lamps are used, then he prefers 
 that a tube or hollow passage should be conducted down to 
 form the shorter leg of the air- siphon, in any convenient 
 direction, and be caused to enter the chimney as before de- 
 scribed, or such channel or passage may be of metal or other 
 material projecting from the walls of the buildings, or it may 
 be down pillars or channels independent of the walls, where 
 the architecture or ornamental portion of the walls or other 
 parts will admit of it ; and, so far from its being necessary 
 that there should be any bell over the chimney of a gas-burner 
 or other lamp, the patentee has found, that having close to 
 the top of the glass chimney a lateral tube, opening into the 
 shorter leg of the siphon, is by far the most effectual way of 
 getting rid of the heated air from the lights : the products, in 
 place of rising up and becoming diffused in the room, pass rapidly 
 through the lateral tube into the shorter leg of the siphon. 
 
 Dr. Chowne states, that he has at all times found an up- 
 ward current in the longer leg of his siphon, whether that 
 longer leg consisted of the shaft of a chimney or a pipe run 
 up against the outside of his house, and bent at the bottom, 
 so as to form the shorter leg. This result certainly does not 
 agree with experience ; for, unless means exist for establishing 
 an upward current by the application of heat to some part of 
 the inverted siphon, we must suppose that a descending cur- 
 rent is as likely to exist in the long leg of the siphon as an 
 ascending one. In summer, there is a constant interchange 
 taking place between the air of our apartments and the exter- 
 nal air, by means of the chimney flues, which afford the readiest 
 
198 CHOWNE'S PATENT 
 
 method of intercommunication. Whether the current in the 
 flues be ascending or descending, depends chiefly upon differ- 
 ences of temperature within and without ; but, as the brick- 
 work of chimneys often gets heated by the vicinity of the 
 kitchen flue, or even by the sun shining upon it during the 
 day, an ascending current is more likely to be sustained than a 
 descending one, since brick-work will retain its heat for many 
 hours. When, according to Dr. Chowne's arrangement, the chim- 
 ney opening is stopped up with the exception of an aperture for 
 receiving the short leg of the siphon, the following phenomena 
 are likely to take place. If, during the day, the room be occu- 
 pied, and its temperature be raised by the respiration of the 
 occupants, and the doors and windows be kept tolerably close, 
 there will be an upward current in the chimney which will 
 draw upon the air of the room, and ventilation will go on. 
 As evening advances, and lamps and candles are introduced, 
 the doors and windows still being closed, the increased elas- 
 ticity of the air of the room arising from these sources of heat 
 would be likely to counteract any tendency of the air to de- 
 scend the chimney or long leg of the siphon. In fact, the 
 system of ascending currents which has been perfectly main- 
 tained during the day, is strengthened and supported by 
 night, in consequence of the increased elastic force of the air 
 of the room maintaining and assisting the ascending current ; 
 and hence, ventilation will be maintained by night as well as 
 by day j and even, when the lights are all extinguished and 
 the occupants have retired, the temperature of the room 
 being greater than that of the outer air, ventilation would 
 still go on up the chimney, although in a more feeble manner, 
 provided the doors be kept closed. If the doors were left open, 
 the room would gradually cool down, and the ventilating 
 system might possibly be overturned by a descending current. 
 In fact, this system of ventilation seems closely to resemble 
 the cases mentioned at pages 87, 88, where two fires are burn- 
 ing in one large room ; if one burn well and the other badly* 
 and the doors and windows be tight, so that there is not a 
 
INVERTED SIPHON. 199 
 
 sufficient supply of air in the room to support combustion, the 
 briskly burning fire will draw upon the chimney of the badly 
 burning fire, and the air will be drawn down its shaft to make 
 up the supply. Or a strong kitchen fire badly supplied with 
 air, will draw upon the other chimneys of the house whenever 
 a door is left open. In Dr. Chowne's arrangement, when once 
 an upward current is established, the long leg of his siphon is 
 in the condition of a briskly burning fire, and the room or 
 space to be ventilated is in the condition of the badly burning 
 fire, whose shaft is drawn upon to supply its more vigorous 
 neighbour.* 
 
 The statement, that there is always an ascending current in 
 the long limb of the siphon, except occasionally during gusts 
 of wind, we should be disposed to doubt. If an inverted 
 siphon of large bore be erected in the middle of an open plain, 
 far from any artificial disturbing causes, and the long limb be 
 from 20 to 50 feet high, and the short limb only a few feet 
 high, there is no reason why there should be any current at 
 all within the tube, so long as the enclosed air were of the same 
 temperature as that on the outside. But if the sun shone 
 upon the tube, an ascending current would be generated j 
 if a very cold wind blew upon it, or if after rain the evapora- 
 tion from the surface were strong, and by such means the tube 
 were greatly reduced in temperature, a descending current 
 would probably be established. 
 
 The whole system, however, is ingenious, and deserves 
 attention. The writer had an opportunity of seeing this 
 ventilator in action at one of the evening meetings of 
 the Pharmaceutical Society, on the 15th of May last, and it 
 seemed to be very efficient. A number of gas-burners ar- 
 ranged round the short leg of the siphon, discharged into it 
 
 * At the time of revising this sheet, the writer is sitting in a study 
 in which lamps have been burning for some hours. There is no fire in 
 the study nor in an adjoining dining room, which is separated from it 
 by a wall, and yet the chimney of the study draws upon the chimney 
 of the dining-room, for there is a strong downward current in the latter, 
 and an ascending current in the former. 
 
200 TREDGOLD'S SIPHON. 
 
 all the products of combustion so completely, that the hand 
 could be held immediately over the glass chimney of any one 
 of the burners without the slightest inconvenience, and a 
 piece of white writing paper, permanently fixed an inch or 
 two above each chimney, was neither blackened nor scorched. 
 Many years ago, Tredgold recommended a siphon for with- 
 drawing the foul air from the interior of apartments. " If an 
 inverted siphon," he says, " be placed with one leg in the 
 chimney, so near to the fire, that the air in that leg will be 
 warmer than the air in the other leg, motion will take place ; 
 for the air will ascend in the warm leg and go up the chim- 
 ney, and a descending current in the cool leg will take the air 
 from the room. To render the application of this principle 
 successful, the mouth of the tube should be at the ceiling of 
 the apartment ; the lowest part of the curve should be, as 
 much as convenient, below the point where the heat is applied ; 
 and the aperture through which the air flows into the chim- 
 ney, should be formed so that the soot may not fall down the 
 tube : also, the mouth should have a register to close it, or 
 regulate the ventilation." 
 
 CHAPTER II. 
 
 ON THE VENTILATION OF BUILDINGS, SHIPS, MINES, ETC., BY 
 MEANS OF ARTIFICIAL HEAT. 
 
 AMONG the special contrivances for producing ventilation, 
 combustion occupies a prominent part. By applying heat to 
 the air in the upper part of the ventilating tube, the air of the 
 place requiring ventilation is drawn upwards with increased 
 rapidity, and fresh air rushes in with a proportional increase 
 of rapidity to supply its place. This method of producing 
 artificial ventilation seems to have been first described by 
 Rodolphus Agricola, in the sixteenth century. In his book, 
 De re Hetallica, he speaks of the method of drawing the foul 
 
VENTILATION BY ARTIFICIAL HEAT. 201 
 
 air out of a mine, by suspending a large fire in the middle of 
 the shaft, a method which has been practised in mines ever 
 since his time. This method does not appear to have been 
 adopted in the ventilation of crowded rooms, until the year 
 1723, when Dr. Desaguliers was requested to endeavour to 
 improve the arrangements made some years before by Sir 
 Christopher Wren, for the ventilation of the House of Com- 
 mons. Wren's plan was as follows : a large square hole was 
 made in the ceiling at each corner of the house, and over each 
 hole, in the room above, was erected a hollow truncated pyra- 
 mid, six or eight feet high, constructed so as to be closed at 
 pleasure. The vitiated air of the house escaped by these 
 holes when the temperature was sufficient for the purpose ; 
 but it often happened that the colder and denser air of the 
 upper room not only stopped the ascending current, but 
 poured down in cataracts upon the members below. This 
 defective arrangement was remedied by Dr. Desaguliers, in an 
 ingenious manner. He constructed a closet at each end of the 
 upper room between the pyramids, and conducted a trunk 
 from the pyramids to the square iron cavities that surrounded 
 a fire-grate in each closet. When, therefore, the fires were 
 lighted in these grates, air ascended from the house, 
 through the heated cavities, into the closets, and was thence , 
 discharged up the chimneys. This arrangement is represented 
 in Fig. 76, in which c c are the pyramids at one extremity of 
 
 Pig. 76. 
 
 : 
 
 he room, opening from the ceilings of the house ; e e, two 
 pipes leading from them to the fire-grate, a b. The heat of the 
 fire, rarefying the air in the iron cavities, x x , a current would 
 be produced in e e, and the air from the pyramids would 
 flow out at x x into the closets, and thence into the chimney. 
 
 K5 
 
VENTILATION OF SHIPS. 
 
 The principle of this arrangement is perfectly sound, and 
 there is no doubt that it would have answered the purpose 
 required, if it had had fair play. The cause of its failure is 
 curious. Mrs. Smith, the housekeeper of the House of Commons, 
 feeling herself aggrieved at being disturbed in the possession of 
 " her rooms," discovered an easy method of persuading the 
 honourable members that the philosopher's plan had failed. 
 She carried her point, " by not having the fires lighted until 
 the house had sat some time, and was very hot ; for then the 
 air in the closets that had not been heated went down into the 
 house, to an air rarer and less resisting, whereby the house 
 became hotter, instead of being cooled. But when the fire 
 had been lighted before the meeting of the members, the air 
 went up from the house into the closets, and out of their 
 chimneys, and continued to do so the whole day, keeping the 
 house very cool." The failure of this plan led to the intro- 
 duction of the rotatory fan, already noticed (page 182)."* 
 
 About the time of the controversy between Dr. Desaguliers 
 and Dr. Hales, respecting the merits of their machines for 
 ventilating ships, as described in the last chapter, a new rival 
 appeared, with a contrivance which far exceeded either of 
 theirs, in point of practical utility, from the circumstance of 
 its being self-acting. Mr. Samuel Sutton, a brewer, being 
 moved with compassion towards the unhappy soldiers who 
 were suffering in the ships at Spithead for want of fresh air, 
 felt himself "obliged to do all that was possible for their 
 relief in these unhappy circumstances," and even submitted to 
 all sorts of slights and humiliations rather than forego his 
 laudable desire to benefit mankind in general, and the navy 
 
 * " Sir George Beaumont and some other members observing that 
 the design of cooling the house was frustrated, asked me in 1736," says 
 the Doctor, " if I could not find out some contrivance to draw the hot 
 and foul air out of the house by means of some person that should 
 entirely depend upon me, which I promised to do, and effected ; calling 
 the wheel a centrifugal or blowing ivheel, and the man that turned it a 
 ventilator." 
 
BY ARTIFICIAL HEAT. 203 
 
 in particular, by the introduction of his apparatus. Without 
 at all desiring to call in question the humane motive of 
 Mr, Sutton, it must still be confessed, that in the introduction 
 of his apparatus, he had a keen eye to his own interest. Not 
 that this is objectionable in any inventor, for there can be no 
 doubt that a benefit conferred by a man upon his country, is 
 deserving of reward ; but the mixed motive is objectionable 
 urging the invention forward on the plea of humanity, and, at 
 the same time, asking for a large pecuniary reward. When 
 Dr. Arnott advocates the general introduction of his inven- 
 tions, on the ground of humanity, the motive is pure and 
 honourable, for he takes out no patent, and hints at no reward ; 
 he seeks only to be useful to his fellow-creatures. 
 
 Mr. Sutton's invention is, however, very meritorious, and 
 in his curious and amusing narrative,* we read a minute 
 account of its origin and progress. It originated in the fol- 
 lowing circumstance. In a room which had three fire-places, 
 the windows and doors were made to fit as tightly as possible, 
 so as to exclude the external air. Having made a large fire 
 in two of the fire-places, it was found that the wind came 
 down the chimney of the third fire-place with such force, as to 
 blow out a candle. This suggested the idea of ventilating 
 the different parts of a ship ; for as a fire is always kept burning 
 on board, it was supposed that a pipe or cavity opening from 
 any part of the ship to the fire, would draw the air along 
 it to feed the fire, thus occasioning a fresh supply to the part 
 of the ship whence the air was subtracted. This idea being 
 once conceived, Sutton sought every opportunity of consulting 
 naval men on the subject of the ventilation of a ship. On 
 
 * An Historical Account of a New Method for extracting the Foul 
 Air out of Ships, &c. By Samuel Sutton. London, 1745. A second 
 edition was published in 1749, containing two favourable accounts of 
 the invention, read before the Royal Society by Dr. Mead and Mr. Wat- 
 son, and a Discourse on the Scurvy, by Dr. Mead who thought that 
 that fatal disease would be greatly mitigated by the introduction of 
 Sutton's apparatus on board ships. 
 
204 BUTTON'S METHOD OF 
 
 one occasion, he says, "being at a coffee-house near the 
 Admiralty, I placed myself nigh some gentlemen of the navy, 
 and inquired of them, as I had before of others, as to the use- 
 fulness of the forementioned change of air, who all, to a man, 
 acknowledged that it would be of the utmost service, and upon 
 their unanimous approbation of it, I told them that I could 
 procure such a change of air : upon which one of the company 
 went to another table, and the rest followed him ; and I heard 
 him tell the others, that he heartily pitied me as being really 
 mad, and out of my senses." Button had solicited an inter- 
 view with the Lords of the Admiralty, which was granted, and 
 he received a letter of introduction to Sir Jacob Ackworth. 
 On presenting it, a meeting was appointed five days afterwards 
 at seven in the morning. The brewer was punctual, but the 
 knight kept him waiting the whole day, and it was not till the 
 evening that he condescended to exchange a few words with 
 him : " Sir, I suppose you intend to throw air into the wells 
 of ships f ' " No ; I propose to draw it out by means of fire." 
 " Do you know how far you are to draw it out T " Not six 
 inches ; for if I can extract it never so small a distance, the 
 incumbent air will press forward, of course, and cause a con- 
 stant change." Sutton then expressed a hope that a time 
 might be appointed for a trial of his scheme, but the knight 
 replied that no experiment should be made, if he could hinder 
 it. This unmannerly treatment did not daunt the brewer. 
 He petitioned the Lords of the Admiralty, and obtained an 
 order to make an experiment in a ship of war at Woolwich. 
 Whereupon he proceeded to erect his apparatus, and had com- 
 pleted it, except the soldering of two pipes, when a messenger 
 from the builder of His Majesty's yard appeared, and ordered 
 the workmen ashore. In spite of all remonstrances, the work 
 was suspended, and next day the apparatus was taken down, 
 and the holes were plugged up. Under these discouraging cir- 
 cumstances, Sutton introduced himself to Dr. Mead, the king's 
 physician, who at once encouraged the scheme, and succeeded 
 in getting Martin Folkes, the President of the Royal Society, 
 
VENTILATING SHIPS. 205 
 
 to favour it. Under this powerful patronage, the Admiralty 
 were induced to order a trial to be made of the apparatus on 
 board any of His Majesty's ships in the river. Accordingly, 
 Sutton fixed upon the hulk at Deptford, but he had great 
 difficulty in getting his orders executed ; the workmen of the 
 King's Yard " were busily employed in trying the usefulness 
 of another machine, industriously set on foot to supplant 
 mine ;" " the excessive shyness and caution of the gentlemen 
 of the yard led me to conclude that my scheme at last would 
 be set aside, in spite of all the steps I could take to prevent 
 it ; and I was confirmed in this opinion when I found the 
 pipes were made of wood between five and six inches wide, in 
 such an unworkmanlike manner, that to render them tight, I 
 was forced to get siza and paper from Deptford to put over 
 the joints j and that, moreover, many hands were employed in 
 erecting wind-sails, in order to shew that they could thereby 
 procure as much air as nay scheme would afford." But, at 
 length, in September, 1741, the trial was made before some of 
 the Lords of the Admiralty, the Commissioners of the Navy, 
 Dr. Mead, Martin Folkes, Esq., and several other members of 
 the Royal Society. Sir Jacob Ackworth welcomed this dis- 
 tinguished company, by remarking, " I am sorry that you 
 are come to see the trial of such a foolish experiment, that I 
 tried myself yesterday, and it would not shake a candle." 
 Sutton ventured to reply that the apparatus would be in good 
 humour that day, and that the en,d of every one of the pipes 
 would blow out a candle. The experiment was accordingly 
 made, and although Sutton complains that the tarpaulins 
 which he had placed over the hatches had been removed, the 
 success was complete, and his friends were satisfied.* The 
 
 * Mr. Watson reported to the Royal Society, that Sutton's machine 
 brought up air " from the bread-room, orlop and well of the ship at the 
 same time, in such quantity, that large lighted candles being put to the 
 end of the tubes, the flame was immediately sucked out as fast as applied, 
 though the end of one of the tubes was above 20 yards distant from the 
 fire." 
 
206 
 
 BUTTON S METHOD OP 
 
 result of this trial was, that, in November following, Sutton was 
 sent by the Lords of the Admiralty to Portsmouth to fit up 
 his apparatus in the Norwich, man of war. Sir Charles Wager 
 gave him a letter to the Commissioner at Portsmouth, in which 
 he sensibly remarks, " this contrivance is approved by much 
 wiser men than I am in such things, and, therefore, I desire 
 you would let Mr. Sutton have all the encouragement and 
 assistance you can give him." He also requests that Sutton 
 may " meet with no obstruction or discouragement from any 
 body that may think themselves wiser." After this, as may 
 be supposed, Sutton had nothing to complain of in the Ports- 
 mouth dockyard. 
 
 Sutton now thought it high time to ask for a " suitable 
 reward for his -useful invention, and reasonable satisfaction for 
 his trouble, loss of time to the neglect of his other affairs, and 
 expenses in the execution of the same." He plied the Admi- 
 ralty with petitions, but received no answer until the llth 
 June, 1743, when he was furnished with an extract from a 
 letter from the Captain of the Norwich, containing his report 
 as to the working of the apparatus, on a voyage to the Coast 
 of Guinea, the West Indies, and back. The Captain's report 
 is as follows : " As to the air-pipes which were put on board 
 of me, I was obliged to stop up two of them, by reason the 
 fire came down between decks the other, to the well, was 
 kept open ; but the ship making water enough to keep her 
 sweet, I was not able to judge of their use, having been so 
 healthy as to bury only two men all the time I was on the 
 coast." The healthy state of the crew, during such a voyage, 
 was, at the period to which we now refer, something so extra- 
 ordinary, that the Captain's report, which was intended to 
 condemn the scheme, is really a high eulogium on it, seeing 
 that one of the pipes was allowed to remain open during the 
 whole voyage. 
 
 At length the Admiralty made their report, in which they 
 stated that the apparatus " does not, in all respects, come up 
 to the expectation, and that the use thereof is dangerous and 
 
VENTILATING SHIPSv 207 
 
 liable to accidents by fire, yet as the said Mr. Sutton has 
 employed a great deal of pains and time about the said inven- 
 tion for the benefit of the navy, and had encouragement from 
 their Lordships to do so, and their Lordships, being desirous 
 to give encouragement to persons who shall turn their thoughts 
 to any inventions that may tend to the advantage of the navy," 
 directed him to be rewarded with the sum of one hundred 
 pounds ! Of course Mr. Sutton was very much disappointed, 
 and very angry. He attributes his failure to the undue 
 preference given to Dr. Hales' ventilators. 
 
 Mr. Sutton received the hundred pounds " on account," and 
 did not cease to urge the merits of his invention upon the 
 Admiralty, until he got an order to have his apparatus fitted 
 to several ships. He then looked out eagerly for the reports 
 of their respective commanders, and was fortunate in get- 
 ting a favourable return from Admiral Boscawen, dated Table 
 Bay, 9th April, 1748, in which he says, "I cannot help think- 
 ing the air-pipes fixed in the men of war have been of great 
 service, by purifying the air between decks, and thereby prevent- 
 ing the scurvy." After this, the career of Sutton was crowned 
 with success, which he modestly attributes to "the wisdom 
 and zeal of the present Right Honourable the Lords of the 
 Admiralty, and the Right Honourable and Honourable the 
 principal officers and Commissioners of His Majesty's Navy, 
 who having taken the whole affair into their serious conside- 
 ration, were so thoroughly satisfied of the great advantage 
 that must accrue to the nation from the faithful execution of 
 my scheme, that they have contracted with me for fixing my 
 engine on board His Majesty's ships, whether laid up or in 
 commission." As Sutton makes no further complaint we 
 must suppose he was satisfied with the pecuniary part of the 
 arrangement : as to his zeal for the good of his country, which 
 he talks so much about, he took care that no one but himself 
 should derive pecuniary benefit from the plan, by securing 
 his invention by a patent.* This, however, at length, proved 
 
 * The application of the machine, as stated in the patent, is for re- 
 
208 BUTTON'S METHOD OP 
 
 more fatal to the scheme than the powerful opposition of Sir 
 Jacob A ck worth, and the cool indifference of the Lords of the 
 Admiralty. Sutton charged 30 for each ship of the Royal 
 Navy, or of the East India Company, into which the appara- 
 tus was proposed to be introduced ; and as this was thought 
 too much for a benefit which many persons in authority were 
 disposed to question, the scheme was abandoned in a year or 
 two, and, after the death of Sutton, all trace of its existence 
 seems to have been eradicated from the minds of ship-builders 
 and seamen, and Sir Jacob was left in undisturbed possession 
 of his favourite wind-sails. 
 
 Mr. Watson's paper, which was read before the Royal 
 Society, contains a very good account of Sutton's invention, 
 He describes the copper used for boiling the ship's provisions, 
 and the method of fixing it, with two openings below > divided 
 by an iron grate. The first opening, having an iron door, is 
 for the fire, the other for the ashes. In ordinary cases, the 
 combustion of the fire is supported by air drawn through the 
 ash-pit ; but, on board ship, as both the fire hole and the ash- 
 pit hole are furnished with doors to prevent the escape of fire, 
 the air must be supplied by some other means. Accordingly, 
 
 one or more holes, r s, Fig. 77,* are 
 made through the brick-work in 
 the side of the ash-pit, u, and 
 tubes of lead or copper are fitted 
 closely therein, and conducted 
 from thence into the well, and 
 other parts of the ship ; thus drawing off therefrom the foul 
 air, and sending it through the fire, v, it escapes up the chim- 
 
 moving noxious air from " mines and caverns in the earth, dungeons, 
 prisons, and all infected places." It may also be used in " hot-houses 
 and walls, which will greatly warm the earth for the speedy production 
 of its fruits, and also in granaries, for the preservation of corn and grain." 
 * In the plan, Fig. 78, B is the ash-pit, E E the copper pipes opening 
 into it, c the oven, D a vent-hole, and K K the pipes, continued to any 
 part of the ship. 
 
VENTILATING SHIPS. 
 
 209 
 
 Fig. 78. 
 
 ney. At the same time, a supply of fresh air rushes in at 
 openings about the ship, to occupy the place of the bad air. 
 This circulation of air not only goes on while the fire is burning, 
 but so long as the fire-place, copper, or brick- work remain 
 warm, as was observed on board the hulk at Deptford, when 
 the draught of air through the tube lasted above twelve hours 
 after the fire was taken away. " This being considered, as the 
 dressing the provisions for a number of people will take up 
 some hours every day, the warmth of the brick-work and flues 
 will continue a draught of air from one day to the next, Mr. 
 Sutton proposes thus to circulate the air by the same 
 and no greater expense of fire, than is customarily used 
 
 for the necessities of the 
 ^ ship." The larger the ship, 
 // the greater the number of 
 men on board, and the larger 
 the quantity of provisions, 
 so that more time and fuel 
 will be required in preparing 
 them, and the more perfect 
 will be the ventilation. The 
 size and number of the tubes 
 is of little consequence, for 
 the larger the tubes, and the 
 greater their number, the less 
 the velocity of the air, and vice 
 versa. Mr. Watson notices, as 
 an essential condition of the 
 perfect action of the tubes, 
 that both the fire door and the 
 ash-pit door be kept closed. 
 In large ships there is not only 
 a copper, but also a fire-grate^ 
 L, (Fig. 78) like that used in 
 kitchens. Behind this grate, 
 copper tubes, F F, were also 
 
 
 
 
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 X 
 
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210 VENTILATION OF STEAMERS. 
 
 fixed and carried through the brick-work, so that one extremity 
 thereof projected about a foot into the chimney, G,and the other 
 end opened into the hold, or any other part of the ship ; so that 
 the air rushed along this tube into the draught of hot air in 
 the chimney. To obviate the objection to the space occupied 
 by these tubes on board ship, it is advised that only one tube, 
 of a convenient size, be attached to the side of the ash-pit, 
 and, as soon as it passes through the main-deck, to give it the 
 fprm which occupies least room ; and from this main tube, 
 branches might ramify to different parts of the ship, these 
 branches being carried between the beams which support 
 the deck, till they meet the sides of the ship, where they 
 could be conducted also between the beams into the places 
 intended. 
 
 How admirably adapted is this plan to the ventilation of 
 steamers. A large central trunk might be made to feed the 
 furnace, and into this trunk smaller branches from every cabin 
 and sleeping birth might discharge their foul air, and thus 
 maintain every part of the vessel in a state of perfect salu- 
 brity. That Button's plan has not been entirely forgotten, is 
 evident, from its having been applied in order to get rid of 
 the offensive effluvia arising from the coppers of soap-boilers, 
 tallow-melters, and similar occupations, which often become a 
 nuisance to a whole neighbourhood. The copper is set in the 
 usual manner, and the furnace and ash-pit, furnished with 
 doors, so as to admit of being perfectly closed ; the lid of the 
 boiler is made to fit very tight, and a pipe rising from it is 
 carried into a channel which opens into the ash-pit ; the 
 ftid matters rising from the boiler, are in this way made to 
 pass through the fire into the smoke-flue. This plan is said 
 to have answered perfectly, so that a factory which was for- 
 merly most offensive, became entirely free from offensive 
 odours. 
 
 In the two schemes thus detailed, that of Dr. Desaguliers, 
 for ventilating the House of Commons, and that of Mr. Sutton, 
 for ventilating ships, &c., we have the principle of ventilating 
 
VENTILATION OF THE HOUSE OF LORDS. 211 
 
 by artificial heat carried out with perfect success. A large 
 number of plans have been subsequently contrived on the 
 same principle, many of them made subjects of patents ; and, 
 although it is more than probable, that the respective in- 
 ventors not only did not copy them from, but had never heard 
 of either of the plans above described ; yet, as they are iden- 
 tical in principle, and very similar in detail, it is not necessary 
 to particularize them. A few examples, however, may be no- 
 ticed of the ventilating of public buildings, and as the House 
 of Commons has often been made the subject of experiment 
 in this way, as already noticed, it may be interesting to state 
 a few particulars respecting the warming and ventilation of 
 the House of Lords. 
 
 Sir Humphry Davy having been requested to devise some 
 scheme for the purpose, submitted to the Lords Commissioners, 
 in February, 1810, his proposals; and in September, 1811, in 
 a letter to the Earl of Liverpool, he thus briefly recapitu- 
 lates the heads of his plan : " To convey fresh air into the 
 House, I propose flues of single brick connected with the flues 
 for sending hot air through the vaults under the floor, and I 
 propose that this fresh air should be admitted by numerous 
 apertures in the floor of the House, and supplied to the flues 
 by pipes of copper or plate iron from the free atmosphere. 
 The air in this case will be always fresh, and, by regulating 
 the fire, may be more or less heated, according as the tem- 
 perature of the room is low or high. 
 
 " To carry off the foul air, I propose two chimneys, or tubes 
 made of copper, placed above the ventilators, and connected 
 with wrought iron tubes, which can be heated by a small fire, 
 if a great draught is necessary, as in cases when the House 
 is full. 
 
 " Should this plan be adopted, there would be no necessity 
 for opening windows ; the foul air would be carried off from 
 above j warm air or cold air, whichever is necessary, may be 
 supplied from below, and there would not be, as now, any 
 stagnation of air." 
 
212 
 
 VENTILATION OP THE 
 
 The plan accompanying this letter, of which the above is an 
 
 extract, is shewn in Fig. 79. 
 v is one of the ventilating 
 apertures in the ceiling of the 
 House, covered with a chimney 
 of copper, c ; this is continued 
 by an iron tube, i, which passes 
 through a small furnace, F. c 
 is another copper tube con- 
 nected with the iron one. The 
 upper end of this tube, was 
 only one foot in diameter; it 
 opened into a cowl on the roof. 
 The furnace, F, was contained 
 in a fire-proof house erected 
 for the purpose on the roof. 
 
 This plan does not seem to 
 have been very successful ; for 
 
 Mr. Adam Lee, in his Report to the Lords' Committee, in 
 June, 1813, states, that on very crowded nights, it was im- 
 possible, by means of the present ventilators, to draw off the 
 heated air ; the temperature in the House frequently rose to 
 80, and would have been higher if the windows had not been 
 open. Instead of the ventilation pipe, one foot in diameter, 
 it was proposed to erect enlarged pipes of three feet diameter, 
 furnished with registers to close them, to prevent cold air from 
 blowing into the House when the ventilation was not wanted. 
 These pipes were to be conveyed in an oblique direction to 
 the fire-proof house, and to be capped at the top with a cowl- 
 head. The fire to the ventilator was considered unnecessary, 
 and even objectionable, on account of smoke getting into the 
 House down the ventilator. " I have, at various times, taken 
 an opportunity," says Mr. Lee, " of going on the top of the 
 House, and have put my head over the ventilation pipe when 
 the fire was at full heat, and have not perceived the hot air 
 coming from the House. I have likewise tried, at other times, 
 
HOUSES OF PARLIAMENT. 213 
 
 without fire, and have found a very strong current of hot air 
 from the body of the House.* 
 
 Mr. Lee's plan for ventilation was tried and failed. There 
 is no doubt, that after abolishing the furnace, and introducing 
 wide tubes, a down current was as likely to be admitted into 
 the house as an ascending current out of it ; and the contriver 
 himself, who thought himself a wiser man than Sir Humphry 
 Davy, has afforded a sufficient satire on his own improvements, 
 by proposing to place rotatory wheels in his wide tubes, in 
 order to make them discharge the air the right way. It is 
 satisfactory to learn, that their Lordships did not accede to 
 this proposal. They consulted Mr. James Wyatt, the archi- 
 tect, who made some changes in the House, and erected some 
 apparatus. This perished injthe fire in 1834, which led to the 
 destruction of both Houses. 
 
 In the following year, a Select Committee of the Commons 
 examined a number of witnesses, consisting chiefly of scientific 
 and practical men, with a view to discover the best, or, at 
 least, a good method of warming and ventilating the New 
 Houses of Parliament about to be erected. In their Report, 
 the Committee advised that some plan should be systemati- 
 cally adopted before the commencement of the new buildings, 
 from a conviction, that whatever plan should afterwards be 
 selected, " provision should be made for its adoption, in the 
 first instance, by the architect, so as not only to insure its suc- 
 cess, but to prevent needless expense and inconvenience ;" and 
 that, for this purpose, " the whole space immediately below 
 the two Houses, as well as that between the ceiling and the 
 roof, be prepared and altogether reserved for such arrange- 
 ments as may be necessary for the object in view." The 
 plans proposed by Dr. Reid, were favourably noticed, and it 
 
 * In this Report, it was also stated, that the flues were arranged 
 horizontally round the chamber of the House, 100 feet in length and 
 upwards, and that the smoke remained in them for a considerable 
 time, sometimes producing a strong smell of sulphur in the House 
 itself. 
 
214 REID'S METHOD OF VENTILATING 
 
 was recommended that some, if not all, of his alterations 
 should be submitted to the test of actual experiment, " as the 
 only means of ascertaining with accuracy the soundness of the 
 principles laid down in the evidence, and their useful applica- 
 tion to the future Houses of Parliament." 
 
 The temporary building for the House of Commons having 
 been found very defective, in respect both of warmth and ven- 
 tilation, this building was placed at the disposal of Dr. Reid. 
 It had been warmed by the ordinary warm water system : the 
 large flat tablets through which the water circulated were 
 placed in a room under the House, -and occupied a surface of 
 about nine feet square ; they were four feet high. 
 
 Dr. Reid's arrangements were as follows : Two or three 
 feet beneath the floor of the House, a second floor was formed, 
 containing about twenty apertures each about eighteen inches 
 square. Beneath the second or lower floor, is a long passage, A ; 
 opening into this, are two others of an equal width, B and c ; in 
 the passage, B, is placed the warm water pedestal. Large folding 
 doors are placed before the entrances, and within these pas- 
 sages ; the temperature of the house above depends on the 
 relative adjustment with each other of these folding-doors. 
 Fresh air, either warm or cold, according to the season, can be 
 produced ; and it can be changed from warm to cold, or the 
 contrary, as the variable external temperature of the day or 
 hour requires. This will be understood by referring to the 
 section (Fig. 80), and the plan (Fig. 81). The fresh air enters 
 from Old Palace-yard, through the perforated wall, D. If the 
 folding-doors 1 and 2 are opened, and all the rest closed, the 
 air will enter the passage, A, passing through the pedestals 
 placed in B, and warm air only will be supplied to the house 
 above. If air moderately warmed be required, the doors 3 
 and 4 are opened in addition to 1 and 2, and two currents, 
 one cold and the other warm, are then produced, which meet 
 and blend together in the passage, A, and then ascend. If air 
 of the external temperature only be required, the doors 3 and 
 4 are alone opened. If required to be only moderately warmed, 
 
THE TEMPORARY HOUSE OF COMMONS. 215 
 
 3 and 4 are opened, 1 half opened, 2 closed ; the small folding- 
 doors, 5 and 6, are then opened, and a slight current of warm 
 air passes through the small passage E, and mixes with the 
 cold current entering at c. The folding-doors in this passage 
 can likewise be opened when 3 and 4 are closed, and a cur- 
 rent of warm air will then be conveyed to one end of the 
 passage A. 
 
 The air, whether warm or cool, rises through the apertures 
 a a a, into the space beneath the real floor of the house. 
 Immediately over these openings are large platforms, sup- 
 ported by short feet, the effect of which is to disperse the 
 great body of air admitted. The air then enters through 
 openings made in the actual floor of the house, these open- 
 ings being exceedingly small, very close together, and about 
 300,000 in number. They are about one-sixth of an inch in 
 diameter on the surface of the floor, but expand down- 
 wards, to prevent their being stopped with dirt or dust. 
 The sides of the House under the galleries are battened or 
 brought forward five or six inches, and in the space thus 
 formed between the framing and the wall, the air ascends and 
 passes out through the floors of the members' galleries, per- 
 forated for the purpose in the same manner. The floor of the 
 House and galleries is covered with a thick horse-hair mat- 
 ting with large meshes, to allow the air to ascend through 
 them. 
 
 The force which sets this great body of air in motion, is 
 the ventilating shaft, G, in which a powerful upward current 
 is generated by means of a large fire, as will presently be 
 explained. 
 
 In summer, when the air transmitted into the House is 
 required to be cool, various contrivances can be resorted to in 
 the chamber immediately behind the perforated wall, D. The 
 air might be made to pass into the chamber A, over wet sur- 
 faces, and be cooled by evaporation, or ice may be suspended 
 in netting between the piers in the chamber. 
 
 A new ceiling was also constructed a few feet below the. 
 
REID'S METHOD OF VENTILATING 
 Fig. 80. 
 
THE TEMPORARY HOUSE OF COMMONS. 217 
 
 former one, for the purpose of favouring the transmission of 
 sound. This ceiling is divided into three portions, the cen- 
 tral portion being horizontal from one end to the other ; the 
 other two compartments inclined so as to make an angle of 
 30 with the floor of the house. These two inclined portions 
 are glazed, but the centre is panelled, so as to assist in the 
 ventilation of the House. An inclination has also been given 
 to the ceiling beneath the members' galleries, corresponding 
 exactly with the inclination of the lateral compartments in the 
 newly constructed ceiling above. 
 
 The ventilation of the House is accomplished in the follow- 
 ing manner : Each panel of the centre compartment of the 
 ceiling is raised by blocks several inches above their styles, 
 thus admitting the air of the House into the space, F, between 
 the two ceilings. The rapid removal of this vitiated air, and 
 the consequent rushing in of fresh air from below, is effected 
 by the large shaft, G, erected in Cotton Garden, at a distance 
 of about 20 feet from the eastern wall of the building. About 
 ten feet from the surface of the ground is a very large coke or 
 coal fire, which produces a powerful current up the shaft. 
 Now the space, F, between the two ceilings of the House, 
 opens at the north end into a large square shaft, which is con- 
 tinued downwards, and opens underground into the circular 
 shaft, G. The consequence of this arrangement is, that when 
 the current of hot ascending air is produced in the circular 
 shaft, there is a downward draught through the square shaft, 
 thereby rapidly withdrawing the air from within the House, 
 and causing the fresh air to rush into it from openings in Old 
 Palace-yard. A damper at b, in the square shaft, regulates 
 the draught in the shaft, G, and consequently, as it is more or 
 less opened, the supply of air to the house can be regulated 
 according to the number of members present. 
 
 The height of the ventilating turret above the ground is 
 110 feet : it is 12 feet in diameter at the base, and about eight 
 feet at the summit. 
 
 The system thus described, has been in operation for some 
 
 L 
 
218 REID'S METHOD OF VENTILATING 
 
 years, and may, we think, be pronounced as one of the most 
 extensive, and, upon the whole, one of the most successful 
 experiments in the warming and ventilation of a building that 
 has been made in this country. The arrangements are made 
 with considerable skill, and display a good knowledge of the 
 subject. That they have not been completely successful need 
 not excite surprise, when it is considered that the plans of some 
 of the most eminent scientific men have been partial failures. 
 That Dr. Reid should have failed in doing what he proposed 
 to do in the case of every building which he took in hand is 
 no wonder, when it is considered that each building presents 
 its own peculiar set of difficulties, and that the facilities are either 
 very few or absent altogether ; for, as Dr. Birkbeck remarked, 
 in his evidence before the Committee, " Heating and ventila- 
 tion, especially the latter, seldom enter into the mind of the 
 builder when he projects his building ; he begins as if he did 
 not know that ventilation could be necessary ; he trusts to the 
 doors and to the windows, to neither of which belongs the 
 business of ventilation. The doors admit the occupants to 
 the chambers ; the windows the light j and apertures ought to 
 be introduced to admit air for ventilation as regularly as the 
 other openings." Or, as Dr. Faraday remarked in another place, 
 " " The builder makes the doors and the windows to fit as 
 tightly as possible, and then the poor chemist is called in 
 to provide fresh air." Under such circumstances, the poor 
 chemist can only do his best. The laws of nature will not 
 accommodate themselves to him ; he can only apply them as 
 far as they admit of application in a building, where every 
 thing seems to have been arranged for the express purpose of 
 defeating their operation. And even when the best arrange- 
 ments are made which the circumstances will admit of, their 
 efficient working requires the constant superintendence of a 
 man of intelligence, instead of an ordinary stoker or porter. 
 For if the room, or court, or hall, or church, or whatever it 
 may be, be very crowded, the ventilation must be promoted as 
 much as possible, and the warming restrained. If, on the 
 
THE TEMPORARY HOUSE OF COMMONS. 219 
 
 contrary, the building contain only a few persons, and the 
 external temperature be low, the warming must be increased, 
 and the ventilation diminished. To meet all the circum- 
 stances of the case, for summer and for winter, for night and 
 for day, without any assistance from the architect who de- 
 signed the building, and your arrangements constantly ex- 
 posed to defeat, by careless attendants leaving doors open, or 
 by people constantly coming in or going out to do all this to 
 the satisfaction of every one, is a task which few scientific 
 men would undertake. It is now the fashion to cry down Dr. 
 Reid, and to call him by all sorts of ugly names : this is very 
 easy, as is every kind of criticism which consists in mere 
 abuse and fault finding ; but, although we are no partisans of 
 Dr. Reid, we venture to state our opinion, that in the case of 
 the temporary House of Commons, where all the arrangements 
 were left in his own hands, he has succeeded in the proposed 
 object of removing the vitiated air, and keeping up a constant 
 supply of warm or cool air to fill its place. The following 
 extract from a Parliamentary document contains, in few words, 
 both the praise and the censure of this system, and with this 
 we take leave of the subject. 
 
 " A strong current of prepared air is now admitted, imme- 
 diately under the entire surface of the floor, which is pierced 
 with many thousand holes : after passing through these aper- 
 tures, the air is again distributed into many millions of other 
 holes, by means of a hair-cloth carpet, through which it is drawn 
 up towards the ceiling, where admirable arrangements have been 
 made by Dr. Reid, for discharging it through apertures in the 
 edges of the panels ; and thus the foul air is carried rapidly 
 along a tunnel to feed the great furnace which creates this 
 current of ventilation. It is obvious, that the air so drawn 
 up through the hair-cloth carpet must be charged with par- 
 ticles of ground dust or mud from the members' feet ; and 
 that (so impregnated), it must be inhaled by those within its 
 reach. I heard many members complain that it rests upon 
 their faces, and enters their eyes, and nostrils, and mouths ; 
 
 L 2 
 
220 
 
 VENTILATION OF THEATRES. 
 
 and from woful experience, some members know that it can 
 find its way to their lungs."* 
 
 In theatres and similar places, where a large central 
 chandelier is used for the purposes of illumination, advantage 
 may be taken thereof as a powerful ventilating agent. This 
 was done many years ago by the Marquis of Chabannes, who 
 was engaged to warm and ventilate Covent Garden Theatre, 
 Fig. 82. and his arrangements will be understood 
 
 by referring to Fig. 82, in which a is the 
 chandelier; d, a pipe of wrought iron for 
 the purpose of carrying off the heat and 
 the products of combustion ; e, a wooden 
 case, into which air flows at o and s from 
 the ceiling ; m m, pipes which conduct the 
 vitiated air from other parts of the house, 
 In one of the galleries was placed a furnace, 
 the combustion of which was supported by 
 the vitiated air from several tiers of boxes. 
 A similar furnace was placed over the stage, 
 and the gas chandelier ventilated the cen- 
 tre. The vitiated air from all parts of 
 the house was discharged above the roof, 
 through three trunks, each terminating in 
 a cowl, u. The air admitted into the 
 theatre, to replace that which was carried 
 off by this powerful ventilating apparatus, was warmed by 
 means of a furnace, called a calorifere, placed at every entrance 
 and staircase which communicated with the external air. The 
 stage, and the parts behind the curtain, were warmed by steam 
 cylinders placed below the stage. Calorifers were also placed 
 at every other point, whence a draught of cold air was likely 
 to issue. The effect of all these arrangements was, upon the 
 whole, satisfactory, and it is certain that this theatre was 
 
 * Sir F. Trench to Viscount Duneannon. Par. Pap. No. 204, 
 Kess. 1838. 
 
VENTILATION OF LIGHTHOUSES. 221 
 
 better warmed and ventilated than any other in London. 
 Complaints, of course, were made. The atmosphere of the 
 house was said to have a dry and stifling effect; and, no 
 doubt, in cold weather the air must have been dry, for if 
 admitted at and below the freezing temperature, and then 
 warmed to 65 before it was inhaled, it would feel dry. But 
 those who complained most loudly, probably, never inquired 
 whether pure dry air at 65 is not far better fitted for the 
 purposes of respiration, than the vitiated air of crowded 
 assemblies, the moisture of which is of the most offensive 
 character. 
 
 The preceding details will sufficiently illustrate the prin- 
 ciple upon which ventilation is conducted when fire or flame 
 is used as the force to give motion to the ventilating current. 
 The use of hot water, steam, &c., as ventilating agents, will be 
 noticed in the next chapter. There are one or two special 
 applications of ventilation, in which flame and fire are con- 
 cerned, which belong to this chapter ; these are the ventila- 
 tion of lighthouses and of mines. 
 
 Until within the last seven or eight years, no provision was 
 made for the ventilation of lighthouses, a neglect or oversight 
 the more extraordinary, when it is considered that the 
 efficiency of a lighthouse depends on the brilliancy of the light 
 exhibited, and this, in its turn, depends on the perfection of the 
 combustion. If no means be taken to carry off the products 
 of combustion, they must accumulate within the lantern, and 
 greatly interfere with the usefulness of the light, as well as 
 injure the health of the attendants. 
 
 Let us consider for a moment what a lighthouse is, and 
 what are the nature and amount of the products of combustion 
 generated within it. A lighthouse may be defined as a small 
 room raised to the top of a tower sufficiently strong to resist 
 the action of the waves and wind, as in the Eddystone, and 
 the wind in all cases ; to bear all the beating and pelting of 
 the storm, and yet to be only walled with glass. Within 
 this transparent room or lantern, a brilliant light or many 
 
222 FARADAY'S SYSTEM OF 
 
 brilliant lights must be kept constantly burning during six- 
 teen hours on a winter's night, and during eight hours in 
 summer. According to one arrangement, a large and very 
 powerful lamp is fixed in the centre of the lantern, and this 
 burns or consumes from 12 to 14 pints of oil in one hour. 
 According to another arrangement, 20 or 30 small Argand 
 lamps, each with a polished reflector behind it, are mounted 
 on a revolving frame, and these consume from 15 to 20 pints 
 of oil in one hour. 
 
 Now as oil in every 100 parts contains 78 parts of carbon, 
 11.5 parts of hydrogen, and 10.5 of oxygen, it will be seen 
 that the products of combustion must chiefly consist of water 
 and carbonic acid. Now there is enough hydrogen in lib. of 
 oil to produce rather more than lib. of water ; because, 1 part 
 of hydrogen combines with 8 parts of the oxygen of the air 
 to produce 9 parts of water. 
 
 The 78 parts of carbon in lib. of oil will, in like manner 
 produce 2 T 8 Q 6 Q-lbs. of carbonic acid; that is, the carbon will 
 deprive the air of nearly 31bs. weight of its oxygen, thus 
 spoiling ISJlbs. or 172^ cubic feet of air, by depriving it of 
 its oxygen. 
 
 Such being the products of combustion of lib. of oil, it 
 is easy to ascertain the products of the combustion of 1 9 T 6 
 pints of oil, the quantity consumed per hour in the Tynemouth 
 lighthouse. The most obvious inconvenience arises from the 
 water, of which not less than 20 fluid pints are produced per 
 hour ; for that is the given quantity, if the vapour, as it is 
 given off, were condensed. Now the lantern itself, in cold 
 weather, affords a powerful means of condensation, especially 
 when a cold frosty wind is blowing upon it. In such case, the 
 vapour is not only condensed into water, but the water is 
 frozen, and the plate glass of the lantern is often covered with 
 a crust of ice, varying from a quarter to half an inch in thick- 
 ness. If this ice were perfectly pure and transparent, it would 
 dim and distort the light ; but the vapour of water from the 
 oil carries with it minute particles of carbon or soot, which 
 
VENTILATING LIGHTHOUSES. 223 
 
 condense with the water, and become entangled with the ice, 
 thereby producing a further opacity. The carbonic acid is 
 chiefly injurious to the attendants. The men at the Eddystone 
 lighthouse told the writer, some years ago, that during the long 
 nights of winter, they had great difficulty of breathing in the 
 lantern, and that the " foul air" descended into the sleeping 
 apartment below, and produced great inconvenience. They 
 also complained of the enormous amount of labour which 
 they had every morning in cleaning the glass panes of the 
 lantern, and the difficulty of getting rid of the ice. It was 
 sometimes even dangerous to scrape it off, from the risk of 
 fracturing the glass. 
 
 The attention of the Trinity Board had long been directed 
 to the removal of these evils, and about the year 1842, they 
 requested Dr. Faraday to turn his attention to the subject. 
 He did so, and after visiting various lighthouses, and making 
 himself master of all the facts of the case, he devised a 
 remedy as simple and complete as could be desired. The re- 
 sults of his investigation were given by him to the members 
 of the Royal Institution, in a lecture, on Friday evening, the 
 7th of April, 1843, which the writer had the privilege of 
 attending. 
 
 In those lighthouses containing a single lamp in the centre 
 of the lantern, the remedy consisted in lengthening the chim- 
 ney of the lamp, or rather in placing over the glass chimney a 
 tube of sheet iron, and carrying it through the roof of the lan- 
 tern into the open air, the upper extremity of this tube being 
 defended from the weather by a cover of some kind. In the 
 other arrangement, a central chimney was also constructed, 
 and over the glass chimney of each lamp was placed one ex- 
 tremity of a small tube, and this tube was curved in such a 
 way, that the other extremity opened into the central chim- 
 ney. These tubes, one for each of the 20 or 30 lamps, were 
 supported by the frame which carried the lamps and their 
 reflectors, and as the frame revolved, the ends of the tubes 
 described each a small circle within the central chimney 
 
224 FABADAY'S SYSTEM OF 
 
 without touching it. In this way the small tubes carried off 
 all the products of combustion, without interfering with the 
 reflectors. The result in both cases was perfect, the central 
 chimney over the large lamp carried off all the products of 
 combustion ; and the short tubes over the lamps in the re- 
 volving lights also discharged the products of combustion into 
 the central chimney, and this conveyed them to the outer air. 
 The consequence was, that the interior of the lantern was 
 always dry and healthy, and the windows remained perfectly 
 bright. This system, as Dr. Faraday well remarked, may be 
 called an adaptation of sewerage to the atmosphere ; aerial 
 sewers are employed to carry off the refuse of the spoiled air, in- 
 stead of allowing it to accumulate in the house or apartment. 
 The success which attended this simple and beautiful appli- 
 cation of ventilating chimneys, suggested to Dr. Faraday its 
 introduction into dwelling-houses, for the purpose of completely 
 and effectually discharging into the external air the products 
 of the combustion of gas lamps. He was, moreover, incited 
 to this, in consequence of an application from the Managing 
 Board of the Athenaeum Club, who found that in the library 
 of that institution, the bindings of many of the books, espe- 
 cially of those on the upper shelves, were very much corroded, 
 an effect which was attributed to the products of combustion 
 arising from the gas lamps with which the library was lighted. 
 Now lib. of ordinary London gas produces, during combustion, 
 as much as 2|lbs. of water, rather more than 2ilbs. of 
 carbonic acid, and takes from the atmosphere 2^1bs. of 
 oxygen; thus spoiling 19-Hbs. of air, or 251 cubic feet. But 
 in addition to these products, sulphurous acid is also sometimes 
 produced, owing to the presence of certain sulphurous com- 
 pounds, which are not wholly removed in the process of puri- 
 fication. This sulphurous acid, in contact with the air, becomes 
 converted into sulphuric acid, which attacks walls, furniture, 
 books, &c. Dr. Faraday collected some of the watery products 
 of combustion from the gas-burners at ( the Athenaeum, and 
 found it to contain sulphuric acid ; the ventilating tubes 
 
VENTILATING LIGHTHOUSES. 225 
 
 placed over the flame were corroded by the acid water in the 
 places where it condensed, and formed a solid sulphate within 
 the tube, of iron or of copper, according to the metal used. 
 But Dr. Faraday did not attribute the corrosion of the books 
 entirely to this source, but partly also to the heat, and partly 
 to certain substances used by the leather dresser. 
 
 It is common to see in shop windows large glass bells sus- 
 pended over the glass chimneys of gas-burners. These are, of 
 course, of no use in carrying off the products of combustion, 
 but merely serve to prevent the flame from blackening the 
 ceiling. But if a pipe from the top of each lamp be led out 
 into the open air, or into the chimney of the room, not only 
 are the products of combustion carried away, but the gas- 
 burners themselves often become powerful and efficient venti- 
 lators to the whole apartment, instead of being, as before, a 
 powerful source of vitiation. The inconvenience to be guarded 
 against is the condensation of water in the pipe, for at a short 
 distance from the gas flame, the watery product of combustion 
 becoming cooled, condenses into water before it reaches the 
 extremity of the ventilating tube ; and if the tube ascends all 
 the way from the burner, the water will even flow back and 
 extinguish the flame, or otherwise annoy the persons in the 
 room. 
 
 But as the appearance of these ascending ventilating tubes 
 in a room is rather unsightly, Dr. Faraday got rid of them 
 altogether, by making the hot air from each burner descend 
 instead of ascending. This he accomplished by furnishing: 
 each burner with two concentric glass chimneys of unequal 
 height, the lower one being the interior. The exterior or 
 higher of the two chimneys is covered with a plate of mica, so 
 as to prevent the draught from ascending higher than the top 
 of this chimney. The descending current is established by 
 applying heat to the bend of a ventilating tube, fixed at the 
 bottom of the two chimneys, and turning upwards among the 
 ornaments of the chandelier. When this current is fully 
 established, the gas is lighted, and the mica plate placed over 
 
 L 5 
 
226 VENTILATION OP 
 
 the outer chimney. Each Argand burner is supplied with air 
 in the ordinary way, through the centre, and the products of 
 combustion are carried from the top of the inner chimney, 
 down through the space between that and the exterior chim- 
 ney, then along the descending ventilating tubes up into a 
 central vertical shaft, which serves also to suspend the chan- 
 delier and to enclose the gas pipes ; the products of combus- 
 tion are then received into a box above, and from this proceeds 
 a pipe into the open air. A globe of ground glass, open only 
 at the bottom, is placed over each lamp, and has an elegant 
 though unusual appearance. It is said, that the two glass 
 chimneys produce more perfect combustion, and, consequently, 
 a greater amount of light, than with an ordinary Argand 
 burner, with only one chimney. The flame is certainly larger, 
 and of a redder colour than the ordinary gas flame. 
 
 The ventilation of a coal mine is regulated on the principle 
 of descending and ascending draughts. The reader is aware 
 that those enormous deposits of coal which form so large and 
 important a portion of the mineral wealth of Great Britain, 
 are called coal-fields, in which the coal, situated at various 
 depths from the surface, is separated into a number of distinct 
 layers or strata, of various thicknesses, by means of layers or 
 strata of slaty clay, called shale, and coarse hard sandstone, 
 called grit, forming altogether what are called coal-measures ; 
 or, in other words, beds of sandstone, shale, clay, and coal, lie 
 one above another, in repeated alternations, to a great depth. 
 The strata of coal, however, technically called seams, are very 
 thin, compared with the other associated beds. Though ex- 
 tending under large tracts of country, they are often only a 
 few inches thick, and never more than six or eight feet, 
 except one seam in Staffordshire, which is thirty feet. But 
 the interposed strata of grit and shale often exceed 700 feet 
 in aggregate thickness. Under this series, is the mountain 
 limestone, forming various calcareous strata of variable thick- 
 ness, sometimes exceeding 900 feet. This limestone rests on 
 a bed of old red sandstone, varying in thickness from 200 to 
 
COAL MINES. 227 
 
 2,000 feet. The term, coal-formation, sometimes includes 
 these two great series of strata, although, in general, the coal 
 measures lie above them, the lowest coal-seam commonly rest- 
 ing immediately on the mountain limestone. 
 
 The various deposits which form the coal-measures, do not 
 occur in regular horizontal unbroken planes. When first 
 deposited, they were doubtless in this condition, but, at various 
 times, this horizontal position has been disturbed by some up- 
 heaving force from below, whereby the coal-measures have, in 
 many districts, been made to assume the shape of a huge 
 trough or basin, rising on all sides from a central point, the 
 sides of the basin being composed of sandstone or limestone, 
 and the middle filled up by strata superior to the coal-measures, 
 such as magnesian limestone, and new red sandstone. Now, it 
 must follow from this arrangement, that the edge or boundary 
 line of each stratum must appear at the surface somewhat like 
 the concentric layers of an onion cut in two. This " coming 
 to the day," or appearance of the coal at the surface of the 
 ground, is called the basset or outcrop, and serves to determine 
 the outer form or side of the basin. But the internal up- 
 heaving force (whatever it may have been) which converted 
 the horizontal strata into basin-shaped arrangements, seems, 
 at the same time, to have produced certain fissures or fractures, 
 often nearly vertical, and stretching through the whole mass. 
 These rents are called dykes, because they divide the seams or 
 bands of coal into fields, and some of them are so considerable, 
 as to find a place in geological maps. 
 
 In order to ascertain where the deposit of coal is most 
 advantageous for working, boring is resorted to, and when the 
 spot is determined, a cylindrical or elliptical shaft, from 10 to 
 15 feet in diameter, is sunk. The depth may vary from 25 
 fathoms (150 feet) to 300 fathoms (1,800 feet) before the 
 seam intended to be worked is reached. When this is done, 
 the sinking of the shaft is discontinued, and a broad straight 
 passage, called a lord or mother-gate, is driven from it into the 
 seam of coal in opposite directions. This bord is 12 or H 
 
228 GENERAL DESCRIPTION OF 
 
 feet broad, and of the whole height of the seam, so as to expose 
 the rock above, which is now called the roof, and also the 
 stratum below, which forms the thill or floor. It is also 
 necessary to drive a passage, called the drip-head, dip-head, 
 or main level for collecting the water of the mine. From this 
 level gallery, numerous other galleries are driven towards the 
 rise of the strata, till they reach either the outcrop of the 
 seam, or the dip-head gallery of an adjoining colliery. The 
 direction of the bords is arranged so as to follow the natural 
 cleavage of the coal, which forms their sides, and, consequently, 
 is not always at right angles with the dip-head. When a bord 
 has been excavated some distance, narrow passages, called 
 head ways, are driven from it, at regular intervals, on both 
 sides, and exactly at right angles, if the natural cleavage of 
 the coal be cubical, as it generally is ; and when these have 
 been driven eight or ten yards, they are made to communicate 
 with other bords, which are opened parallel to the first, and 
 on each side of it. In this way, the bed of coal is entirely 
 laid open, and intersected by broad parallel passages, about 
 eight yards apart, communicating with each other by narrower 
 passages or headways, which cross them at right angles, and 
 also traverse the whole extent of the mine, breaking up 
 the seam into immense square or rectangular pillars, which are 
 left standing between the two. In this state, a coal mine has 
 been aptly compared to a regularly built town, the bords 
 being the principal streets, the headways the narrower streets 
 which cross them, while the pillars of coal form the masses or 
 blocks of buildings. 
 
 As these pillars of coal form frequently as much as three- 
 fourths, and never less than one-third of the whole seam, many 
 methods have been contrived for removing them without 
 danger. The best method of working, is that called panel- 
 work, by which the mine is divided into districts or panels, 
 separated from each other by walls of coal forty or fifty yards 
 thick. The coal is extracted from each in succession, begin - 
 usually with the one most distant from the shaft. Larp;e 
 
A COAL MINE. 229 
 
 pillars of coal are first left between the bords to support tlie 
 roof ; the pillars themselves are then removed, the roof being 
 supported in the mean time by wooden props, and the place 
 where these props replace a pillar is called a jud. In time, 
 the jud is remove i, and then the unsupported roof of the 
 mine falls in. The heap of ruins thus occasioned by the 
 successive drawing of contiguous juds, is called a goaf. Cor- 
 responding with this heap of rocky fragments, and produced 
 by it, is a cavity in the mine, like an inverted basin, including 
 a thin belt of air, which surrounds and partly permeates the 
 goaf. This has been the source of dangerous accidents, as will 
 be noticed hereafter. 
 
 Fig. 83 is the plan of one story of such a mine, in which 
 
 the panels, a a a a, are not entirely laid open by galleries ; 
 b b are laid open, but no pillars as yet removed j in c c, the 
 pillars are being extracted, and the roof is falling in, its ruins 
 forming a gdaf; the panel, d, is entirely worked out and 
 abandoned . 
 
 When the prospects of the mine appear to be favourable, 
 another shaft is, in some cases, sunk at some distance from the 
 first, and when a communication has been established between 
 
230 DANGERS OP WORKING 
 
 them, one is made the downcast, and the other upcast ; that is, 
 the air is conducted from the downcast shaft through all the 
 bords and workings, which it is made to traverse in succession 
 by means of stoppings or doors, in various places, to obstruct 
 its passage and give a proper direction to the current in pass- 
 ing to the upcast shaft. The force which sets this ventilating 
 current in motion, is a large fire kept constantly burning in 
 some part of the upcast shaft. The supplies of fresh air, pass- 
 ing into a mine, must, of course, vary considerably. In the 
 Wallsend colliery, they vary from 2,000 to 3,000, and occa- 
 sionally 3,800 cubic feet per minute. In some of the large 
 workings, the air has to traverse many miles of gallery before 
 it reaches the upcast shaft, and is frequently twelve hours in 
 doing so, moving at the ordinary rate of 2 or 2^ feet per 
 second. Many coal mines are worked without this second 
 shaft, its place being supplied by dividing the single shaft into 
 two distinct portions, by means of an air-tight partition, called 
 a brattice, one division being downcast, and the other upcast. 
 The larger shafts (those 15 feet in diameter) are sometimes 
 divided into three parts, one of which is used for raising the 
 coal to the surface, another for working the pumps for the 
 drainage of the mine, and a third for ventilation, for bringing 
 up the air that has passed through the workings. 
 
 The necessity for perfect ventilation in a coal mine is more 
 urgent than in other mines, on account of the escape from 
 the coal of large quantities of carburetted hydrogen gas (called 
 fire-damp by the miners), which, mingling with the air of the 
 mine in certain proportions, forms a mixture which explodes 
 on contact with flame. This gas is very much lighter than 
 common air, mingles readily with it, and when poured out 
 into the workings, moves along with the ventilating current 
 in the direction of the upcast shaft. The quantity of gas 
 thus poured out is very considerable, but subject to great 
 variation, some seams being more fiery, or full of gas, than 
 others ; and, in working these fiery seams, it is not uncommon 
 for a jet of inflammable gas to issue from every hole made 
 
A COAL MINE. 231 
 
 for the gunpowder used in blasting. But, in addition to this 
 constant supply, there is danger of sudden discharges from 
 cavities in the coal, laid open by the hewer's pick-axe. The 
 gas issues from these cavities with considerable noise, and 
 forms what is termed a blower. These blowers are sometimes 
 so constant in their action, that the gas is collected and con- 
 veyed by a tube into the upcast shaft, continuing for months 
 or years to pour out hundreds or thousands of hogsheads of 
 fire-damp per minute. When thus provided for, the blowers 
 are not, necessarily, a source of danger ; but when one of the 
 reservoirs containing the pent-up gas of centuries, and con- 
 sequently under an enormous pressure, is suddenly broken 
 open, the gas is set free in torrents, and, mingling with the 
 air of the mine, forms an explosive mixture which the first 
 spark or naked flame may ignite, and thus cause a fearful 
 destruction both of life and property. Nor is the explosioij itself 
 always the thing to be dreaded most ; fof the ignition of the 
 fire-damp kindles the coal-dust, which always exists in great 
 quantities in the passages, and, in a moment, causes the mine 
 to glow like a furnace. This conflagration is necessarily suc- 
 ceeded by vast volumes of carbonic acid, or choke-damp, as it 
 is emphatically called, from its suffocating character, and this 
 destroys those whom the explosion had spared. 
 
 It was to guard against accidents of this character, that Sir 
 Humphry Davy invented his safety lamp, a beautiful and simple 
 contrivance, consisting merely of a common oil lamp, the flame 
 of which is completely enclosed within a cylinder of wire 
 gauze, a substance which will not admit of the passage of 
 flame ; so that although the lamp be introduced into an explo- 
 sive mixture, the flame will not pass through the gauze to 
 ignite it. Of course, the efficacy of the lamp depends on the 
 soundness of the wire gauze, for if this be broken and injured, 
 the flame is not protected ; or if the lamp be moved swiftly 
 through an explosive atmosphere, the flame may be blown 
 against, and even through, the meshes of the gauze, and, in 
 either case, might lead to an explosion. When the lamp burns 
 
232 SYSTEM OP VENTILATION" 
 
 in an atmosphere highly charged with fire-damp, the gas gets 
 within the meshes, and burns with a blue flame, which heats 
 the wire gauze to redness. Even this state of the lamp will 
 not produce an explosion, but of course it was never intended 
 that the workman should go on working with the lamp in this 
 state. The blue flame within the lamp ought always to be a 
 caution to him to retire, until the mine be rendered safe by 
 ventilation. From too great reliance, in all cases, on the Davy 
 lamp, from neglect, and from various other causes, this lamp 
 has disappointed the expectations of those most interested in 
 its use, and experienced men now look for safety rather to 
 improved methods of ventilation than to contrivances for light- 
 ing the mines. The general plan of ventilation now in common 
 use will be understood from the following details, in addition 
 to those already given. 
 
 When a seam is begun to be worked, there is, of course, only 
 one available shaft for ventilation, and this is divided into two 
 portions, as at a b (Fig. 84), for the ascending and descending 
 currents : and as it is not safe for the men to be ever more 
 
 than a few yards in 
 advance of the course 
 of the current, they 
 begin working the 
 seam with two paral- 
 lel bords, connected at intervals by cross passages, which are 
 successively stopped by wooden partitions, c c c, leaving no 
 communication except through the one last opened, or that 
 which is farthest from the shaft. Temporary partitions are 
 also placed at e e, to direct the current to the very spots 
 where the men are at work, as at w w. When the workings 
 are more advanced, the direction of the current through every 
 part, by stoppings or partitions, becomes a matter of no small 
 complexity, as will be seen by the plan (Fig. 85), where the 
 arrows represent the course of the air from the downcast shaft, 
 a, through all the galleries to the upcast shaft, 6. It will be 
 seen, that in most places the current is divided between the 
 
IN A COAL MINE. 
 
 233 
 
 parallel bords j 
 this is called 
 double cours- 
 
 ing, and its 
 advantage is, 
 that if any part 
 of the mine 
 is more fiery 
 or dangerous 
 than the rest, 
 the current can 
 
 there be confined to one course, and thus have its velocity 
 doubled ; while in the parts containing least gas, the same 
 current can be allowed to expand into three passages, which 
 is called treble coursing. The double stoppings in Fig. 85, 
 represent those in which doors of communication are required. 
 These are made in pairs, in order tha* a person may pass 
 through them, as a barge through a canal lock, without allow- 
 ing the main bodies of air to communicate. To ensure this, 
 they are sometimes made even treble, and a boy is placed in 
 charge of each pair or set of three, whose duty it is to prevent 
 them from being all opened at once. 
 
 As it is not safe to allow the foul air from the more fiery 
 parts of the mine to come in contact with the fire at the 
 bottom of the upcast shaft, which sets the whole ventilating 
 current in motion, it is usual to divide the air as it enters the 
 mine by the shaft a, into two distinct currents, one of which 
 proceeds through the passages, e e, into the safe parts of the 
 mine only, while the other, c c, circulates through the fiery 
 parts represented by the lighter shade, including the goafs, or 
 old abandoned workings, which are always the most dangerous 
 receptacles of gas. The purer current alone is allowed to pass 
 through the furnace, /, before entering the upcast shaft, b. 
 The other current is conducted through d, and enters the 
 shaft at a higher level by a tunnel cut obliquely through the 
 roof of the seam, as in Fig. 86, where s represents the upcast 
 
234 DIFFICULTIES OF VENTILATING 
 
 Pig. 86. shaft, B the impure current, 
 
 and A the purer current, 
 feeding the furnace, which, 
 when thus constructed, is 
 termed a dumb furnace. 
 
 The goafs, or abandoned 
 workings, are sometimes of 
 vast extent, and are known to occupy from thirteen to ninety- 
 seven acres of ground. They may be compared to enormous 
 inverted bowls or basins, in which the inflammable gas from 
 various parts of the mine accumulates, and from its lightness 
 occupies, at first, the upper part of the goaf : as it increases in 
 quantity, or even as the atmospheric pressure diminishes, it 
 may suddenly fill the goaf and issue from its lowest edge as 
 from the edge of an inverted bowl, and, mingling with the air 
 of the mine, form an explosive mixture, thus giving rise to 
 many sad accidents. Such appears to have been the origin of 
 the explosion in Haswell colliery, Durham, in September, 1844, 
 by which ninety-five persons perished. Dr. Faraday, who, in 
 conjunction with Sir Charles Lyell, visited the mine after the 
 accident, with a view to devise some remedy against the recur- 
 rence of similar accidents, recommended that the goaf itself 
 be ventilated. He thought it would not be desirable to attempt 
 this by driving the contents of the goaf through any parts of 
 the mine which are occupied by human beings ; but that the 
 goaf cavity might be exhausted of noxious air by means of a 
 pipe, rising as high as possible, from four to eight or ten feet 
 into it, and communicating at its other extremity with the 
 upcast shaft. 
 
 Some interesting remarks respecting this explosion, and on 
 the ventilation of coal mines, were made by Dr. Faraday, at 
 the Geological Section of the British Association, in 1845. Dr. 
 Faraday remarked, that the more he pursued the inquiry into 
 the means of preventing such accidents, the more he was dis- 
 heartened at the apparent hopelessness of finding out any good 
 general remedy. The explosions were not simply the effects 
 
A COAL MINE. 235 
 
 arising from the mixture of gases, but from the combustion 
 of the coal dust and coal gas which the first explosion made. In 
 the fatal case at Haswell, the place where the accident origin- 
 ated had been ascertained, and the progress of the fire could 
 be traced on the scorched beams and props of the galleries, 
 and by the deposits of coke made from the coal dust which the 
 explosion raised. To this circumstance, the great force of the 
 explosion was due, and not to the first escape of gas. A 
 similar explosion had been known to take place in a cotton- 
 wadding manufactory, the whole atmosphere of the place 
 being fired by means of the particles of cotton in it. Of all 
 the workmen killed in the Haswell accident, perhaps not one 
 was really burnt to death, but suffocated by the choke-damp. 
 In one part of the workings, the explosion had produced 
 sharp vibrations, like the firing of gunpowder j and in another, 
 the burning went on slowly, like a common fire. But, al- 
 though two panels were blown into one, and solid stoppings 
 of brick-work thrown down, there was no indication of acci- 
 dent in the shaft. If the stoppings had not been blown down, 
 and the supply of air had continued, the mine would have 
 taken fire, and the men been burnt instead of choked. Since 
 the late investigation, many hundred plans had been sub- 
 mitted, urging ill-considered and contradictory measures. 
 Every part of the Haswell Colliery had been examined, ac- 
 companied by the mine-viewer, and recommendations had 
 been received from the best informed men on the spot ; and 
 they were convinced, that the conditions under which such 
 accidents happen were so variable, that no general practical 
 rule could be obtained. Far more information, however, was 
 required. The plan of splitting the air courses was good, as 
 far as the power of the upcast shaft admitted ; but if carried 
 too far, it would produce stagnant points, which could not 
 be prevented by any arrangement consistently with the ever- 
 moving condition of the works. The abolition of the use of 
 gunpowder and lighted candles, would, in some cases, double 
 the price of coals. But the great source of danger, was the 
 
SYSTEM OF VENTILATING 
 
 Cental condition of the miners. With regard to the present 
 race, this was so hopeless, that nothing could be done for them. 
 Although smoking was strictly forbidden, they had been 
 known to contrive to light their pipes in dangerous workings 
 even from the Davy lamp ; and Dr. Faraday had himself, on 
 one occasion, sat down with an open candle, to watch the pre- 
 parations for blasting, and when he inquired for the gunpowder, 
 was told he was sitting on it. Dr. Faraday expressed his 
 opinion of the safety of the Davy lamp when properly used, 
 and of its being a complete and practical contrivance, to which 
 he would willingly trust his own life, as he had already done 
 on many occasions. 
 
 CHAPTER III. 
 
 ON THE METHODS OF VENTILATING BUILDINGS BY MEANS OF HOT 
 WATER, LOW AND HIGH PRESSURE STEAM, AND BY CON- 
 DENSED AIR. 
 
 TT is proposed, in the present chapter, to give a brief account 
 of the methods which have been contrived for ventilating 
 buildings by means of steam and hot water, at low as well as at 
 high pressures. 
 
 The Houses of Parliament have frequently been made the 
 subject of experiments in the art of warming and ventilation. 
 That the experiments have not always succeeded has been 
 already seen, and the reason, probably, has been in their 
 novelty. The members of either House, whose province it 
 has been to order the erection of the various descriptions of 
 apparatus, cannot fairly be charged with the failure, since it is 
 reasonable to suppose, that if a tried and approved method 
 had existed, it would have been ordered ; and the reports 
 published on the subject, do not disclose any method which 
 may be pronounced perfect. 
 
BY HOT WATER AND STEAM. 237 
 
 The centrifugal wheel of Dr. Desaguliers continued to be 
 used for ventilating the House of Commons, until the year 
 1820, when the Marquis of Chabannes was allowed to under- 
 take the warming and ventilation of the House. He proposed 
 to erect a small furnace over the ceiling, the combustion of 
 which was to be supported entirely by the vitiated air of the 
 House ; but this plan being objected to, he caused a large 
 case or trunk to be constructed over the body of the House, 
 below the roof, into which ventilating tubes were conducted 
 from different parts of the House ; four of these tubes opened 
 from under the galleries, to prevent the stagnation of the 
 impure air in those parts, and six openings in the ceiling led 
 into the main trunk, and were each continued in separate 
 trunks to the top, so that the draught from every part was 
 equal. Sixteen steam cylinders were placed within the main 
 trunk, and the heat thereby produced was intended to rarefy 
 the air in the ventilating tubes so powerfully, as to cause its 
 quick ascent and escape through a large cowl of four feet 
 diameter outside the building. 
 
 The House was warmed by means of twelve steam cylinders 
 ranged under the seats of the House, and the external air was 
 brought to these cylinders by a large air trunk, from which 
 there was a separate branch to each cylinder. 
 
 In these arrangements, there was no deficiency either of 
 heating or of ventilating power. On the contrary, the heat- 
 ing surface seems to have been in excess, and was not under 
 perfect command. At any rate, the atmosphere of the House 
 was declared to be uncomfortable, and, after a few years, 
 another system was tried. 
 
 The use of hot water, as a means of ventilation, was intro- 
 duced by Mr. Deacon, in 1813. The air was drawn from an 
 underground tunnel or cellar, by means of a fan, which forced 
 it into the rooms through small iron or earthenware tubes 
 placed in boiling water. The vitiated air was conducted into 
 a tube or channel at the ceiling, and conveyed above the roof, 
 where it was practicable to do so. Iron plates were also 
 
238 SYLVESTER'S METHOD OP 
 
 sometimes used instead of pipes. They were placed parallel 
 to each other, with a space of about 1^ inch between them. 
 These plates were surrounded by boiling water, and the air 
 rose in the space between them. When cold air was desirable, 
 the pipes or plates were immersed in cold or artificially cooled 
 water, and the air thus cooled was thrown into the room by 
 the fanner. If the room was of large size, the fan had to be 
 turned by a man ; this is, of course, objectionable, because 
 human machines are not always to be depended on, and they 
 are, for such purposes as turning a wheel, expensive. Smaller 
 fans were kept in motion by the elasticity of a spring, or the 
 fall of a weight. Mr. Deacon's apparatus was fixed in some 
 public buildings, but does not seem to have made any per- 
 manent impression on the public mind. 
 
 Among the plans submitted to the Committee of the House 
 of Commons, in 1835, for warming the Houses of Parliament, 
 that of Mr. Sylvester appears to have great merit. It was not a 
 mere theoretical plan, for it had been tried, although on a smaller 
 scale than that now proposed, in the lunatic asylum for Kent. 
 The general principle of this plan is to introduce the fresh 
 air slowly, and in any required quantity, by means of an 
 underground channel, a b (Fig. 87). about 9 feet square, and 
 100 yards in length, which forms a communication with the 
 atmosphere and the basement floor of the building ; the outer 
 extremity of the channel being furnished with a cowl, arranged 
 so as always to have its mouth to the wind. The fresh air 
 flowing along this long tunnel, would receive in winter an 
 accession of about 15 of heat, and in summer it would be 
 cooled to a similar extent. It would then pass into a cockle 
 similar to that of the Belper stove (page 118), where it would 
 be heated to within 5 of the temperature required in the 
 House. From this cockle, it would spread into the space, 
 d d, under the floor, and then rise through a large number of 
 small holes drilled in it, into the body of the House. The 
 vitiated air would then be carried off through a number of 
 openings, i, in the ceiling, arranged so as to be opened or 
 
WARMING AND VENTILATING. 
 
 Pig. 87. 
 
 239 
 
 -W- 
 
 closed at pleasure, by means of a contrivance communicating 
 through x to the basement. The vitiated air, after passing 
 through these openings, would flow into the cavity, n, below 
 the roof, and thence be discharged into the open air by the 
 turncap, o, formed so as to have its mouth always turned from 
 the wind. To ensure the required velocity and direction of 
 the ventilating current, a series of pipes, n, filled with steam or 
 hot water, were to be placed in the cavity of the roof. When 
 it was required to raise the temperature of the House higher 
 than usual, the amount of ventilation was to be diminished 
 by closing the apertures in the ceiling, and allowing the 
 vitiated air to escape through channels, xx, in the walls. 
 The velocity at which it was proposed to set the air in motion 
 through the channel, for supplying the fresh and discharging 
 the vitiated air, was 4 feet per second j but it was to flow 
 into the House at the rate of only half a foot per second, 
 thereby producing a current which would scarcely move the 
 flame of a candle. The area of the apertures distributed 
 throughout the floor would be about 665 feet ; and including 
 the House, the staircases, and corridors, &c., it was calculated 
 that there would be 200,000 cubic feet of air changed six 
 times per houi\ When asked whether he proposed to make 
 
240 PERKINS'S METHOD OF VENTILATING 
 
 any arrangements for securing the purity or cleanliness of the 
 fresh air to be introduced, Mr. Sylvester replied, that it 
 would be extremely desirable to have a communication with 
 some large inclosure for the fresh air, such as a large building 
 like Westminster Hall, between the House of Commons and 
 the outer air, that the air might be admitted into this large 
 inclosure, and allowed to settle and deposit its blacks or 
 smuts, just as water , before being used, is allowed to deposit 
 its mud and sand in a large cistern. 
 
 Most of the plans for warming and ventilating buildings, 
 which have been described in these pages, are on a very large 
 and comprehensive scale, adapted to public buildings, and re- 
 quiring not only a considerable expenditure of money, but 
 also of space for their erection and effective action. By dis- 
 tributing the heated air over the whole of the under surface 
 of a perforated floor, it is thereby distributed throughout the 
 space required to be warmed ; and by providing some powerful 
 ventilating force in connection with the top of the building, 
 also perforated, the warm or cool current can be made to pass 
 through the building with any required velocity. But it is 
 obvious, that such extensive arrangements are not adapted to 
 a small building or a private house. In such cases, different 
 arrangements must be made, and these are not always suc- 
 cessful. If, for example, the air be heated by stoves, and 
 instead of being sent into the room through a perforated 
 floor, it is admitted in small currents at an elevated tem- 
 perature, it ascends rapidly to the ceiling, and expends the 
 greater portion of its heat on that surface, while the lower 
 part of the room remains cold, because airs of very different 
 temperatures do not readily mingle together. On this ac- 
 count, Mr. Perkins recommends, that the tubes used in ven- 
 tilation be placed at or near the floor, by which means the 
 warm air is forced to descend and mingle more intimately 
 with the colder air in the room ; and the warm air having 
 thus parted with its heat, is itself drawn off. When hot 
 water or steam pipes are used, the air can only be moderately 
 
ON THE HIGH PRESSURE SYSTEM. 241 
 
 warmed ; and as the ascensional force in such case is not great, 
 the ventilating openings can be placed at any desired point. 
 
 This plan of placing the ventilating openings near the floor 
 is also recommended, on the score of economy. For, as the 
 ventilating power can only be obtained at the expense of the 
 heating power, much of the heat used to warm the room must 
 be lost, if the ventilating openings be placed in the ceiling. 
 So, also, if the temperature be moderate, the products of com- 
 bustion and respiration may be cooled, and thus deprived of 
 their ascentional force before they have time to escape by the 
 ventilator. 
 
 In the warming of a building, by Mr. Perkins's system of 
 one inch tubes, a forcing power is produced in procuring ven- 
 tilation, and the openings for the purpose can be placed at 
 any convenient point, either singly near the floor, or in con- 
 junction with a second opening at the ceiling. " In the ven- 
 tilation and warming of a private dwelling, I would begin, 
 first," says Mr. Richardson, " with the staircase. This we 
 ought to consider the principal artery of the house ; and 
 if this were well warmed by a current of warm fresh air 
 flowing into it, and a constant change effected by a ventilating 
 outlet, warmed, so as to ensure its effective operation, great 
 part of the business would be effected, as the staircase would 
 supply all rooms not in use with warm air in a sufficient de- 
 gree, and would gradually ventilate the whole building, ren- 
 dering it unnecessary to have further ventilation, except in the 
 principal living and sleeping rooms of the family." But every 
 room in the house might be ventilated, by placing two t or more 
 spare columns of tubing in flues concealed within the thickness 
 of the wall. It will be seen, by reference to Fig. 57, p. 150, 
 that where the flue passes in its course through two or more 
 stories of small rooms, a small opening, about six inches square, 
 made from each room into the flue, would, if provided with a 
 proper outlet at the top, effectually ventilate every room. 
 The flue should, of course, be vertical, and enclose the expan- 
 sion tube at the top, where it should terminate in a tin funnel 
 
 M 
 
242 PERKINS'S METHOD OF VENTILATION. 
 
 provided with a turn-cap, to prevent downward currents of 
 air. As soon as the fire was lighted in the furnace below, all 
 these openings into the flues would become so many artificial 
 fire places, drawing from the room a constant current of cooler 
 air into the flue, which, being warmed to a very high tem- 
 perature by the great quantity of pipe within it, the current of 
 warm air would rapidly ascend into the open air above ; thus 
 affording all the advantages of constant spontaneous ventila- 
 tion. In summer, when the warming effects of this system 
 are seldom wanted, the circulation may be turned off from all 
 the rooms by the stop-cocks, and the effects of the hot pipes 
 be confined within the flues. The ventilation would then be 
 carried on as usual, and no additional warmth be experienced 
 from the action of the pipes. The advantages of this ar- 
 rangement for our changeable climate are obvious, for on a 
 cold day in summer, the stop-cocks being opened, the circula- 
 tion would proceed through the coils in the rooms, and thus 
 raise the temperature as desired. 
 
 Thus it will be seen, that by having a flue of the whole 
 height of the building for the reception of the hot water 
 tubes, the vitiated air can be drawn out of the room at any 
 point. By means of the lower opening, the temperature of 
 the room is equalized, and the effects of currents of unequally 
 mixed air removed or mitigated ; while the upper opening 
 carries off the effluvia of the room. The openings should all 
 be furnished with slides, so that they may be contracted or 
 enlarged at pleasure. 
 
 In large public rooms, the size of the ventilating openings 
 ought to be accurately determined by the architect. They 
 ought to be large enough to allow every person in a crowded 
 room to have a proper supply of air for healthy respiration. 
 In a less crowded state of the room, the openings may be 
 diminished by means of slides. By increasing the temperature 
 in the flues, their ventilating power is, of course, increased, and 
 this may be done by arranging a coil within the flue at each 
 opening. 
 
VENTILATION BY DESCENT. 243 
 
 In connection with this system of warming and ventilating, 
 is a plan, which, at first view, appears to be strange and unna- 
 tural ; namely, that by which the fresh warmed air is admitted 
 into the room by openings near the ceiling, and the vitiated 
 air drawn out through openings near the floor. The advan- 
 tages of this plan, as contrasted with upward ventilation, are 
 stated to be these : with upward ventilation, a great part of 
 the vitiated atmosphere of crowded rooms is liable, by the 
 slightest check or condensation, to be thrown down and 
 mixed with the air, which is already partly unfitted for the 
 purposes of respiration. But let the ventilating current de- 
 scend, we have a bright atmosphere of pure air, which, as it 
 becomes contaminated by respiration, is drawn downwards and 
 discharged. On the other hand, this method of ventilation 
 by descent has been denounced as a " noxious fallacy," because 
 the vitiated air from the lungs having a temperature of 98, 
 naturally rises through the air of the room, which is of the 
 temperature of 60 or under ; and, if forced downwards by 
 any means, must be breathed over again by the occupants of 
 the room, before it can be discharged at the level of their legs 
 and feet, in opposition to the laws of gravity. There is much 
 truth in this objection, and we do not see how it is to be 
 answered, unless the velocity of the outgoing current be so 
 considerable as to amount to a strong wind; and it is, or 
 ought to be, the object of all ventilation, to prevent the mo- 
 tion either of the incoming or outgoing current from being 
 felt. This plan of ventilation by descent has been put into 
 operation at the Model Prison, at Pentonville, where the soli- 
 tary system of discipline is enforced, thus giving rise to the neces- 
 sity of having a separate cell for each prisoner. In each cell the 
 windows are fixtures, and the doors are effectually closed, so 
 that the only mode of introducing the requisite supply of 
 fresh, and of abstracting the vitiated air, must be by artificial 
 means. The objection to applying ordinary modes of ventila- 
 tion, by opening windows or by similar means, is the facility 
 such openings give to the transmission of sound. 
 
 M2 
 
244 VENTILATION OF THE 
 
 The method by which this descending ventilating current is 
 produced, is compared by Major Jebb* to the ventilation of a 
 coal-pit, in which, as already explained, the fresh air entering 
 the down-cast shaft, passes through the numerous galleries 
 and workings of the mine, and escapes by the up-cast shaft, the 
 ventilating force consisting of a large fire in the up-cast shaft, 
 In applying such a system to the ventilation of a prison, the 
 objects proposed to be attained were, 1st, The regular supply 
 of a sufficient quantity of fresh air, and, when necessary, of 
 warmed air into each cell, without subjecting the occupant to 
 any inconvenience from the draught. 2nd, The withdrawal 
 of a like quantity of vitiated air. 3rd, That no additional 
 facilities of communication between prisoners in adjoining 
 cells should be afforded by the means made use of, and, there- 
 fore, that the transmission of sound be carefully guarded 
 against. The reader who wishes to inspect all the details of 
 the arrangements by which these objects are carried out, is 
 referred to Major Jebb's paper, and the copious series of en- 
 gravings by which it is illustrated ; but a general idea of this 
 method may be conveyed by the following remarks, to any one 
 who has studied the various methods of warming and ven- 
 tilating as described in this little volume. 
 
 In the basement story is a case or boiler, with a proportion 
 of pipes adapted to the circulation of hot water, and in con- 
 nection therewith, is a large cold air flue open to the outer air, 
 for supplying air to be warmed in passing over the boiler and 
 pipes. This air then passes right and left along a horizontal 
 flue, under the floor of the corridor of the prison ; and from 
 this flue, a communication is established by small lateral flues 
 with each cell, both on the lower and two upper floors, each 
 small flue terminating in a grating under the arched ceiling of 
 each cell. " The object of making the point of entry at the 
 
 * On Modern Prisons: their Construction and Ventilation. By 
 J. Jebb, Major Koyal Engineers, Surveyor-General of Prisons. With 
 ten plates, 4 to.. Published separately from " Papers on subjects coi .- 
 nected with the duties of the Corps of Koyal Engineers." Vol. VII. 
 London, 1844. 
 
MODEL PRISON, PENTONVILLE. 24-5 
 
 top of the cell instead of at the bottom, and diffusing it 
 through a grating on an extended surface, is, that no unplea- 
 sant draught may be experienced by the occupier of the cell, 
 which, in a confined situation, would be the case, were it 
 brought in at the level of the floor ; and that he may not have 
 any inducement to frustrate the intention of ventilation, by 
 stopping it up." A corresponding quantity of foul air is ex- 
 tracted by means of a grating placed close to the floor of each 
 cell, diagonally opposite the opening by which the fresh air 
 is introduced. This grating covers a flue which passes up the 
 outer wall, and communicates with a main foul-air flue placed 
 in the roof, and terminating in a ventilating shaft rising above 
 the top of the building. By this arrangement, the total 
 lengths of each pair of flues respectively used for introducing 
 fresh air into the cells, and extracting foul air from them, are 
 rendered nearly equal on all the stories. This promotes 
 uniformity of action ; and the advantage due to the ascending 
 system, and to difference both of temperature and altitude, is 
 also secured. " Another provision of some importance should 
 be adverted to. Fresh air should be taken into the main 
 flues, communicating with all the cells in the respective wings 
 or divisions, from the side which happens to be exposed to the 
 wind. The force or pressure produced by a very moderate 
 breeze, combined with the other arrangements and circum- 
 stances which are favourable for ventilation, will generally 
 cause a sufficient current to pass through the cells without 
 any fire being lighted in the extracting shaft for ensuring it. 
 The operation of the system will, by these means, at all times 
 be improved, and a considerable saving of fuel will be 
 effected." The same flues are used for ventilating the cells 
 both in winter and in summer ; -the only difference between the 
 arrangements of the two seasons being, that during the sum- 
 mer, when air is introduced into the cells at its natural 
 temperature, a fire is lighted when necessary in the ventilating 
 shaft ; during winter, when the temperature of the air must 
 be raised, a fire is lighted in the heating apparatus below, the 
 
246 VENTILATION BY MEANS OF 
 
 smoke and disposable heat from which being discharged into 
 the shaft, answer the same purpose. 
 
 It has been shewn, by experiment, in the Pentonville Prison, 
 1st, That from 30 to 45 cubic feet of pure fresh air is made to 
 pass into every cell in a minute, and that this abundant ven- 
 tilation goes on with great regularity. 2nd, That this current 
 of ventilation, and a temperature of from 52 to 60, can be 
 uniformly maintained in the cells during the coldest weather, 
 at an expense of less than one farthing per cell for twenty-four 
 hours, and the summer ventilation, by means of a fire lighted 
 in the extracting shaft, has been kept up at less than half the 
 expense. 
 
 We come now to notice an application of steam to the pur- 
 poses of ventilation, which is, in all respects, peculiar. It was 
 remarked, nearly fifty years ago, by Dr. Thomas Young, that 
 whenever any elastic fluid is forced from a jet with a very 
 small velocity, the stream proceeded for many inches without 
 any observable dilatation, and then diverged at a considerable 
 angle into a cone, and, at the point of divergency, there was an 
 audible and even a visible vibration. When the pressure is 
 increased, the apex of the cone approaches nearer to the orifice 
 of the tube, but no degree of pressure seems materially to alter 
 its ultimate divergency. The distance of the apex from the 
 orifice is not proportional to the diameter of the current ; it 
 appears rather to be the greater the smaller the current, and 
 is much better defined in a small current than in a large one. 
 Popular illustrations of this curious fact may be seen every 
 day. A puff of smoke from a factory chimney, on being first 
 shot out, may often be seen to assume the form of a ring, the 
 diameter of which does not greatly exceed that of the chim- 
 ney, but as it ascends in a still atmosphere, it gradually in- 
 creases in size. In the firing of ordnance on a calm day, 
 these rings may be seen on a grand scale, and still more per- 
 fectly if the mouth of the cannon be greased, and no shot 
 used. The same phenomena may also be observed, on a small 
 scale, in the smoke of tobacco projected from the mouth of a 
 
A JET OP STEAM. 247 
 
 skilful smoker. The rotating clouds of smoke from the chim- 
 ney of a steam-boat, have also a tendency to form these conical 
 rings, but from its abundance and the motion of the vessel, the 
 form is not very defined. But the rings of smoke produced 
 by the combustion of bubbles of phosphuretted hydrogen, shew 
 the structure and motion of these rings very admirably. These 
 hollow rings are seen to revolve on the axis of the cylinder 
 from which they are projected, and gradually expand on rising 
 into the air : each of these enlarging rings may be viewed as a 
 magnified element of the cone issuing from the jet in Dr. 
 Young's experiment. 
 
 It was further observed by Dr. Young, that the stream of 
 air, projected from an orifice, drew into its current light bodies 
 near it, which were free to move. This lateral communication 
 of motion in a fluid stream, was noticed in water by Venturi. 
 This attractive force seems to arise " from the relative situation 
 of the particles of the fluid in the line of the current with 
 respect to that of the particles in the contiguous strata, which, 
 whatever may be the supposed order of the single particles 
 with respect to each other, must naturally lead to a commu- 
 nication of motion nearly in a parallel direction, and this may 
 properly be termed friction. The lateral pressure which urges 
 the flame of a candle towards the stream of air from a blow- 
 pipe, is probably exactly similar to that pressure which causes 
 the inflection of a current of air near an obstacle. Mark the 
 dimple which a slender stream of air makes on the surface of 
 water ; bring a convex body into contact with the side of the 
 stream, and the place of the dimple will immediately shew that 
 the current is inflected towards the body ; and if the body be 
 at liberty to move in every direction, it will be urged towards 
 the current in the same manner as in Venturi's experiment, a 
 fluid was forced up a tube inserted into the side of a pipe 
 through which water was flowing. A similar interposition of 
 an obstacle in the course of the wind, is probably often the 
 cause of smoky chimneys." 
 
 If, instead of the jet of air used in these experiments, we 
 
248 VENTILATION BY MEANS OF 
 
 employ a jet of steam, produced under a pressure of 321bs., to 
 the square inch, the attractive power is very considerable. 
 The steam, as it escapes from the boiler, forms a cone, as in 
 Dr. Young's experiments ; and the quantity of air set in mo- 
 tion is equal to 217 times the bulk of the cone of steam. The 
 force with which the particles of air surrounding this cone are 
 drawn towards it, were illustrated by Dr. Faraday in a lecture at 
 the Royal Institution, in various striking experiments. Hollow 
 balls of one and two inches diameter were drawn into the cone, 
 and sustained floating in the line of its axis even when, by an 
 arrangement of the apparatus, the axis was thrown 35 out of 
 the perpendicular. An upright glass tube, 18 inches long 
 and 1 inch diameter, having one extremity plunged in water, 
 and the other drawn into a capillary jet, was immediately 
 exhausted of its contained air, the water being drawn up from 
 the end of the tube, when the capillary jet was placed within 
 the indraught of air occasioned by the cone of steam. By sur- 
 rounding this cone of steam with a cylindrical jacket, the effects 
 were still more remarkable in increasing the draught power of 
 the jet. The air within the jacket is expelled, and a partial 
 vacuum produced, whereby the air rushes in to supply the 
 vacant space, sweeping before it, in its current, any light 
 bodies, such as paper shavings, hollow balls, &c., and projecting 
 them with considerable force from the top of the jacket.* 
 
 * It was shewn, many years ago, by Clement Desormes, that when 
 steam, under high pressure, is allowed to escape from an orifice pierced 
 in a plate, or the flat side of a boiler, and a flat disc is brought close to 
 this plate, the disc is powerfully attracted to the plate. In this case, 
 the elastic force of the steam issuing from the jet, and which tends to 
 separate the plate and disc, diminishes rapidly in its course from the 
 centre to the edges of the disc ; at the same time, the radial currents, 
 by their indraught, bring the two plates together with a power which is 
 so much greater than the former, that the two surfaces adhere. 
 
 This experiment may be shewn in a popular manner by the following 
 contrivance : Cut a couple of cards each into a disc of about two 
 inches in diameter, and perforate one of them at the centre, and fix it 
 on the top of a tube, such as the barrel of a common quill ; then give the 
 
A JET OF STEAM. 249 
 
 In the arrangements made by Mr. Barry for ventilating the 
 House of Lords, this jacket forms the ventilating shaft, and its 
 value will be seen from the following sketch of the general 
 arrangements for warming and ventilating the House, as 
 gathered from a lecture by Dr. Faraday at the Royal Institu- 
 tion, on the 26th March, 1847, and reported in the Athenaeum. 
 Mr. Barry's plan has been applied to the royal ante-chamber, 
 the House of Peers, and the public lobby. It consists, first, 
 in causing a current of air of regulated temperature to pass 
 beneath the impervious floor of these apartments, and after- 
 wards to rise to a chamber at the top of the building, from 
 whence it is diffused in great abundance, but imperceptibly, 
 throughout the three apartments ; and secondly, in drawing 
 off the vitiated air, and discharging it with great rapidity into 
 the atmosphere. To accomplish these objects, methods have 
 been contrived for 1st, Warming the building through an im- 
 pervious floor, as in the case of a Roman bath. 2nd, Effecting a 
 system of currents. 3rd, Providing means for causing 10,000 
 cubic feet of air per minute to proceed on a prescribed course 
 and regulated velocity. 1st, As to the mode of warming : a 
 steam cockle, supplied from one of Lord Dundonald's boilers, 
 is traversed by a quantity of air tubes firmly fastened into it. 
 The air which passes through these tubes, is the source of 
 warmth. This apparatus, with its furnace, is placed beneath 
 the public lobby, and the current of warm air passes beneath 
 its impervious floor, then beneath that of the House of Peers, 
 and, lastly, beneath the floor of the royal ante-chamber beyond. 
 
 other card a slight bend, and place it over the first, with the convexity 
 upwards, so that the orifice of the tube may be directly under and 
 almost in contact with the upper card ; hold the two cards horizontally, 
 and blow through the tube, it will be found impossible to blow off the 
 upper card. 
 
 The attractive force of the blast of air may also be shewn by placing 
 the upper card upon the table with its concave surface upwards : then 
 bring the other card immediately over it, and blow through the tube ; 
 the card will start up from the table and adhere to the other, so long as 
 the blast is sustained. 
 
 M 5 
 
250 VENTILATION OP THE NEW HOUSE OF LORDS. 
 
 With warmth, the air acquires a certain degree of motive 
 power in the rising parts of the passages, which carries it 
 onward till it reaches the reservoir chambers at the summit of 
 the building ; from thence it is made to pass down into the 
 apartments by their walls, and so distributed, without draught, 
 to be breathed by the inmates of these rooms. This gradual 
 diffusion of the air is accomplished by, 2nd, A system of cur- 
 rents, which are caused by subjecting the air to inequalities of 
 temperature. Descending by the walls of the building, it is 
 cooled by the windows, &c., and thus its velocity downwards 
 is increased. Arriving at the level, at which it is at once 
 heated and deteriorated by respiration, combustion, &c., the 
 air again rises in the centre of the room, and passes through 
 the ceiling into a foul air chamber, which is in connection with 
 a chimney. Through this chimney, the air is driven by a 
 steam jet, which, as already stated, will set in motion 217 
 times its own bulk of air. It was shewn by Dr. Faraday, in 
 this lecture, how the steam cockle employed to give warmth 
 in winter, might, by filling it with water from the Artesian 
 well, become a source of coolness in summer. The advantages 
 of Mr. Barry's method of ventilation are thus summed up. 
 1st, The prevention of local draughts. 2nd, The prevention of 
 the stains and disfigurements resulting from such draughts. 
 3rd, The avoidance of all movement and dispersion of the dirt 
 and dust of the house by currents occasioned in it, which cur- 
 rents, if existing, would tend to render the air impure. 4th, The 
 avoidance of all sudden changes of temperature. Finally, it 
 was noticed that all parts of the house were fire-proof, and 
 that this scheme of ventilation was under a disadvantage, as it 
 had to be adapted to buildings which were not planned with 
 reference to it. 
 
 Objections have been made to the vacuum principle of ven- 
 tilation, on the ground that the air within the room or build- 
 ing thus ventilated is rarer than that without, and that air, 
 even slightly rarefied, occasions languor and uneasiness to 
 persons who are not in robust health, whereas the opposite 
 
VENTILATION BY CONDENSED AIR. 251 
 
 condition, or condensed air, has a bracing effect both on the 
 body and on the mind. Schemes have been proposed, at dif- 
 ferent times, for making air-tight rooms, in which air was to 
 be pumped in or out, according to any degree of pressure 
 adapted to the wants and feelings of the occupant. Thus 
 Dr. Henshaw, in 1664, acting upon one of Mr. Boyle's specu- 
 lations, proposed such a room "by which any person may 
 receive the benefit of a removal to another climate, at any 
 season of the year, without removal from his own house, or 
 neglecting any employment whatever." This air-tight room 
 was to be occupied two or three hours in the morning in 
 chronical cases ; but in acute diseases, the patient might remain 
 in it during the whole course of the disease, as in intermittent 
 fevers, in which case the air was to be rarefied in the cold fit, 
 and condensed in the hot fit. We are not aware whether 
 these fanciful speculations were ever put in practice, but the 
 idea was revived some years ago by Mr. Vallance, who pro- 
 posed to construct air-tight rooms, with an aperture in the 
 ceiling for pumping in the air, and a peculiarly constructed 
 door for admitting the occupants in and out. The doorway 
 was 6 feet high, and 6 feet wide, and was fitted with a cylinder 
 of wood, closed at both ends, and placed upright. In the side 
 was an opening 4 feet wide, and on the opposite side, a similar 
 opening. In the centre of this cylinder was a perpendicular 
 revolving shaft, with four leaves, crossing at right angles, fit-' 
 ting the cylinder as closely as its revolving motion permitted, 
 and yet preventing the escape of the air at the edges. When a 
 person entered the room, he placed himself between two leaves, 
 like a turnstile, and, in this way, interfered as little as possible 
 with the enclosed air. A pipe was fixed to the aperture in 
 the ceiling, and carried through the roof, where it was inserted 
 a few inches into a cistern of water. Air was injected into 
 the room by means of machinery. When the weather was 
 warm, the injected air was cooled by being passed through 
 pipes surrounded by cold water, and if heated air were re- 
 quired, the pipes were surrounded by hot water. As the 
 
252 EFFECTS OF CONDENSED AIR 
 
 fresh air was pumped in, as much vitiated air was forced out at 
 the pipe in the ceiling, and it escaped through the water in the 
 cistern, which thus ingeniously regulated the pressure of 
 the air in the apartment. "When a room is thus filled 
 with condensed air, its expansive force is exerted so that 
 every crevice about it becomes a channel to let air out, instead 
 of into it, and thus draughts are effectually prevented.* 
 
 The advantages of condensed air as a medium of ventilation 
 have also been insisted on by competent authorities of our own 
 days. It appears, from some experiments made on this sub- 
 ject by Dr. Junot, that " when a person is placed in condensed 
 air, he breathes with increased facility ; he feels as if the 
 capacity of his lungs were enlarged ; his respirations become 
 deeper, and less frequent ; he experiences, in the course of a 
 short time, an agreeable glow in his chest, as if the pulmonary 
 cells were becoming dilated with an elastic spirit, while the 
 whole frame receives at each inspiration a fresh vital impulse. 
 The functions of the brain get excited, the imagination becomes 
 vivid, and the ideas flow with a delightful facility ; digestion 
 becomes more active, as after gentle exercise in the air, because 
 the secreting organs participate immediately in the increased 
 energy of the arterial system, and there is, therefore, no 
 thirst." 
 
 Dr. Ure, in advocating the plenum method of ventilation,t 
 gives a curious example of the effects of condensed air upon 
 some workmen engaged in sinking a shaft to a great depth 
 through the bed of the river Loire, near Languin. In this 
 district, the seams of coal lie under a stratum of quicksand, 
 from twenty to twenty-two yards thick, and they had been 
 found inaccessible by all the modes of mining previously 
 attempted. M. Triger, an able engineer, constructed a shaft, 
 encased with strong tubing, formed of a series of large sheet 
 iron cylinders, rivetted together. At the top of this cylinder 
 
 * Vallance, Observations on Ventilation, as quoted by Mr. Bernan. 
 j Supplement to the Dictionary of Arts, Manufactures, and Mines. 
 
ON THE ANIMAL SYSTEM. 253 
 
 was an air-tight ante-chamber, into which air was condensed 
 by forcing-pumps with sufficient force to repel the water from 
 the bottom of the cylinder, and thus enable the workmen to 
 excavate the gravel and stones to a great depth. The com- 
 partment at the top had a man-hole in its cover, and another 
 in its floor. After the men had entered, they shut the door 
 over their heads, and then turned the stop-cock of a pipe in 
 connection with the condensed air in the under-shaft. An 
 equilibrium of pressure was soon established in the ante- 
 chamber by the influx of the dense air from below, whereby 
 the man-hole in the floor could be readily opened to allow the 
 men to descend. Here they worked in air maintained at a 
 pressure of three atmospheres (or 451bs. on the square inch) 
 by the incessant action of leathern valved pumps, driven by a 
 steam-engine. While the dense air thus expelled the waters 
 of the quicksand out of the shaft, it infused such energy into 
 the miners, that they could easily excavate double the work 
 which they could do in the open air. Upon many of them 
 the effects were painful, especially upon the ears and eyes, but 
 before long they became quite reconciled to the bracing atmos- 
 phere. Old asthmatic men became effective workmen ; deaf 
 persons recovered their hearing ; while others were sensible to 
 the slightest whisper.* Much annoyance was at first expe- 
 rienced from the rapid combustion of the candles, but this was 
 obviated by the substitution of flax for cotton in the wicks. 
 
 * Many years ago, Mr. Roebuck and another person allowed them- 
 selves to be shut up in a cavity excavated in a rock, which served as a 
 reservoir of air for equalising the blast of the bellows in an iron foundry 
 on the banks of the river Devon, near Alloa, in Scotland. As much as 
 9,300 cubic feet of air were injected per minute, under a pressure of five 
 inches of mercury. It was found that sound was greatly magnified, "as 
 we perceived when we talked to each other, or struck anything : par- 
 ticularly the noise of the air escaping at the blow-pipe, or waste valve, 
 was very loud, and seemed to return back to us." There was, however, 
 no wind to disturb the flame of a candle, neither was it blown out when 
 it was placed in the eduction pipe of sixteen inches diameter, through 
 which the air passed into the furnace. 
 
254 VENTILATION OF THE EEFOBM CLUB HOUSE. 
 
 In ventilating a building on the plenum method, Dr. Ure 
 recommends that the air be thrown in by means of a fan 
 situated in the basement story,* and instances the method 
 adopted at the Reform Club House, where there is a large fan 
 revolving rapidly in a cylindrical case, capable of throwing 
 1 1,000 cubic feet of air per minute into a spacious subterranean 
 tunnel under the basement story. This fan is driven by a 
 steam-engine of five-horse power. The steam of condensation 
 of the engine supplies three cast-iron chests with the requisite 
 heat for warming the whole of the building. Each of these 
 chests is a cube of three feet externally, and is distributed in- 
 ternally into seven parallel cast-iron cases, each about three 
 inches wide, which are separated by parallel alternate spaces 
 of the same width, for the passage of the air transversely as it 
 is impelled by the fan. " This arrangement," says Dr. Ure, 
 "is most judicious, economising fuel to the utmost degree, 
 because the steam of condensation which, in a Watts's engine, 
 would be absorbed and carried off by the air-pump, is here 
 turned to good account, in warming the air of ventilation 
 during the winter months. Two hundred weight of fuel suf- 
 fice for working this steam-engine during twelve hours. It 
 pumps water for household purposes, raises the coals to the 
 several apartments on the upper floors, and drives the fan 
 ventilator. The air, in flowing rapidly through the series of 
 cells, placed alternately between the steam-cases, cannot be 
 scorched as it is generally with air-stoves ; but it is heated 
 only to the genial temperature of from 75 to 85 Fahr., and 
 it thence enters a common chamber of brick-work in the 
 basement story, from which it is let off into a series of distinct 
 flues, governed by dialed valves or registers, whereby it is 
 
 * As powerful blasts of air are not required for the purposes of venti- 
 lation, a rapid movement of the fan is not necessary. Fans making 
 2,000 revolutions per minute are exceedingly disagreeable from the 
 noise and vibration occasioned by them. Quantity of air, not velocity, 
 is the object, and for this purpose, fans of ten or twelve feet diameter, 
 moving slowly, are to be preferred. 
 
IMPORTANCE OP VENTILATION. 255 
 
 conducted in regulated quantities to the several apartments of 
 the building. I am of opinion that it would not be easy to 
 devise a better plan for the purpose of warming and ventilating 
 a large house." In the top story of the building is a large 
 furnace, the draught of which is intended to draw off the air 
 after it has served the purposes of warming and ventilation in 
 the rooms below. Messrs. Easton and Amos are the contrivers 
 of this system. 
 
 CONCLUSION. 
 
 WE have now nearly reached the limit of the space allotted 
 to us in this Rudimentary Treatise, and are anxious in the 
 few remaining pages again to enforce the necessity of adopt- 
 ing an efficient system of ventilation in our rooms and 
 public buildings. The arrangements for warming are, for 
 the most part, beyond the control of individuals ; these are 
 settled by the house-builder or architect according to an- 
 cient rule, and are adapted to our feelings or prejudices in 
 favour of open fire-places ; but the ventilation of our rooms 
 depends in great measure upon ourselves, and we may be fairly 
 charged with a presumptuous neglect of natural laws, if we 
 fail to make use of some of the simple means for obtaining 
 ventilation which have been detailed in previous chapters. 
 Before science had discovered the pernicious effects of impure 
 air, it was not surprising that people did not ventilate. No 
 plans for ventilation could be laid down on a proper basis, 
 until the composition of the atmosphere had been properly 
 defined : no definite meaning could be given to the word 
 ventilation, until the nature of the air itself was known, 
 and the products of respiration and combustion had been 
 proved to be poisonous.* But no sooner had the beautiful 
 
 * Ventilation was probably first practised in mining districts, as a 
 work of necessity, in consequence of the rapid conversion of the oxygen 
 of the air into carbonic acid, by the respiration of the miners, the com- 
 
256 IMPORTANCE OF VENTILATION. 
 
 experiments of Priestley, Cavendish, and others, made an im- 
 pression on the scientific minds of the day, than means were 
 contrived for ventilation. Thus Cavallo, in his Treatise on the 
 Nature and Properties of Air (4to., London, 1781), quotes 
 from an older work, a method of ventilating a room by means 
 of a small tube opening into it, in or near the ceiling, 
 which might either be carried to the top of the building, or 
 be made to communicate with the external air by a small 
 perforation through the wall at the roof the room, by means 
 of either of which, a proper circulation would be established, 
 and the foul air be carried off. In order to admit fresh air 
 into the room, another opening was made in the ceiling, having 
 a communication with a small pipe that led from thence to 
 the outside of the wall, where it was bent and conducted down- 
 wards till it reached the ground, being left open to commu- 
 nicate with the external air. The cool air would thus be forced 
 in at the lower opening of the tube, and made to ascend into 
 the apartment in proportion to the quantity that escaped 
 towards the higher regions, by means of the ventilator. 
 
 Here we have a plan of ventilation at least seventy years 
 old, and yet, at the present day, ventilation is still discussed 
 and quarrelled over, as if it were some new thing. The 
 proper supply of fresh air is denied to the great mass of the 
 population, because builders, who ought to be perfectly ac- 
 
 bustion of their candles, and the large quantities of irrespirable gases 
 liberated by the gunpowder used in blasting. Mr. Henwood has given 
 a summary of the analysis of eighteen samples of air taken from the 
 mines of Cornwall and Devon, from which it appears, that the propor- 
 tion of oxygen was only 17.067 per cent., while the carbonic acid was 
 0.085; the nitrogen 82.848; and in one instance, the proportion 
 of oxygen was reduced to 14.51 ; and in another, the carbonic acid 
 was 0.23 per cent. These results shew a diminution in the pro- 
 portion of the vital ingredient of the atmosphere from its usual 
 per centage of 21, and an increase of the poisonous ingredient, car- 
 bonic acid, from 0.05, its usual amount, calculated to produce great 
 injury to persons exposed to the breathing of such a fluid for hours 
 together. 
 
GENERAL NEGLECT OF VENTILATION. 257 
 
 quainted with these things, (who ought also to be able to 
 construct chimneys that will discharge their smoke into the 
 air instead of into the room), too often neglect to study the 
 natural laws which chemists and physiologists have placed 
 on a sure basis. We are told that the native porters of 
 Canton are accustomed to balance the load which they carry 
 on a pole upon their shoulders, by means of a large stone 
 at the other extremity of the pole, and that they deemed the 
 suggestion of an Englishman an impertinent interference, who 
 wished them to balance one package by means of another. 
 " Our ancestors," they said, " were very wise men, and 
 they never carried more than one package at a time, and 
 this they balanced by means of a stone ; shall we be wiser 
 than our ancestors T So may a large proportion of our mo- 
 dern builders exclaim, " Our ancestors were very wise men ; 
 they never thought of providing special means for ventilation 
 in rooms and public buildings ; shall we be wiser than our 
 ancestors ?" Many a powerful satire on the modern practice 
 of house-building is afforded by the stifling effects of ordi- 
 nary dwellings. For example, Dr. Macculloch, in his Ac- 
 count of the Hebrides, remarks, that while the inhabitants 
 had no shelter but huts of the most simple construction, 
 which afforded free passage for currents of air, they were 
 not subject to fevers ; but when, through the good in- 
 tentions of the proprietors, new dwellings were erected, and 
 were made close, comfortable, and commodious, the stagnating 
 air, and other impurities, joined to the want of cleanliness in 
 the inmates, generated febrile infection. Now, we think, it 
 must be admitted, that had these new dwellings been properly 
 ventilated, by special means contrived for the purpose, there 
 is no reason why they should have been more unhealthy than 
 the old ones. 
 
 When the great masses of the population become fully alive 
 to the necessity of abundant supplies of wholesome air within 
 doors, then, and not till then, will they also become alive to 
 other sanatory measures ; then will every house be properly 
 
258 THE PROCESS OF RESPIRATION. 
 
 supplied with pure water, efficient sewerage, and special means 
 for letting out foul air and admitting fresh ; then shall we cease 
 to bury our dead in the midst bf the living ; then will cattle- 
 markets, slaughter-houses, and all noxious trades, manufactures, 
 and occupations, be removed to a greater distance from dwelling- 
 houses ; then shall we have boards of public health filled by 
 competent men, and endowed with adequate powers j then will 
 vested rights in injurious abuses yield to public opinion, and 
 the health and well being of the population will be of para- 
 mount interest. 
 
 At the risk of repetition, let us consider the grounds which 
 render a proper supply of pure air necessary to health. In 
 the process of respiration, the blood, in passing through the 
 lungs, is exposed to the action of the atmospheric air, during 
 which exposure it undergoes certain changes. The blood 
 from the right side of the heart, when it enters the lungs, is 
 of a dark red colour ; it is then dispersed in a state of most 
 minute subdivision through the ultimate vessels of the lungs, 
 and in these vessels is brought into contact with the atmos- 
 pheric air, when it becomes of a bright red colour. In other 
 words, the blood changes in the lungs its venous appearance, 
 and assumes the character of arterial blood. The blood thus 
 arterialized, returns to the left side of the heart, from whence 
 it is propelled through the whole arteries of the body. In 
 the minute terminations of the arteries, the blood again loses 
 its florid hue, and, reassuming its dark red colour, is returned 
 through the veins to the right side of the heart, to be exposed, 
 as before, to the influence of the atmospheric air, and to 
 undergo the same succession of changes. 
 
 On examining the respired air, it is found that a portion of 
 its oxygen has disappeared, and a similar bulk of carbonic acid 
 has been substituted. While oxygen gas is passing inwards 
 through the membrane of the lungs, carbonic acid is at the 
 same time passing outwards through the same membrane. 
 In fact, the oxygen of the air is absorbed by the blood, and 
 in some unknown state of combination, reaches the extreme 
 
PRODUCTS OP RESPIRATION. 259 
 
 subdivision of the arteries, where it is united with a portion of 
 carbon, and forms carbonic acid gas, which gas also, in some un- 
 known state of combination, is retained in the venous blood, till 
 in the lungs it is expelled, and oxygen is absorbed in its stead. 
 Along with the carbonic acid, a large quantity of aqueous 
 vapour is at the same time separated from the blood. 
 
 One great object of this process is the production and main- 
 tenance of animal heat. From a comparison made by Professor 
 Miller, of King's College, of the results of numerous experi- 
 ments, it appears that a man of ordinary stature consumes, in 
 the course of 24 hours, 9 ounces (Troy) of carbon ; that the 
 heat generated during the combustion is sufficient to boil away 
 81bs. of water j that the consumption of oxygen in this 
 process is equal to 24 ounces, or 19.4 cubic feet ; that the 
 quantity of air vitiated amounts to 97.2 cubic feet ; and the 
 product in carbonic acid, to 33 ounces. 
 
 These results are, of course, liable to much variation in the 
 same individual at different times, in different individuals, and 
 in different sexes. The quantity of aqueous vapour is also 
 liable to much variation, but the average quantity has been 
 stated to be 3 grains per minute. We have seen that the 
 carbonic acid is a deadly poison, and the water thus 
 given off is not pure water, such as is liberated in the 
 process of distillation or evaporation, but is contaminated 
 with the most offensive animal effluvia. M. Leblanc states, 
 that the odour of the air at the top of the ventilator of 
 a crowded room is of so noxious a character, that it is dan- 
 gerous to be exposed to it even for a short time. If this air be 
 passed through pure water, the water soon exhibits all the phe- 
 nomena of putrefactive fermentation. The water of respiration 
 thus loaded with animal impurities, condenses in the inner 
 walls of buildings, and trickles down in foetid streams. In the 
 close and confined dwellings of the poor, this vapour condenses 
 on the walls, the ceiling, and the furniture, and gives that 
 permanently loathsome odour which must be familiar to all 
 who take sufficient interest in the poor of large towns ever to 
 
260 CONCLUSION. 
 
 enter their dwellings. Take up a chair, and it is clammy to 
 the touch, and the hand retains the ill odour ; and, if the poor 
 people are remonstrated with, on the ground of want of clean- 
 liness, they say that the supply of water is scanty, and what 
 little they have, must be dragged upstairs from the yard or 
 cellar below. The low state of health induced by such abodes 
 produces a chilly sensation, even in summer, which renders the 
 occupants averse to open windows, and, in many cases, in con- 
 sequence of the crowded state of some burial grounds, and the 
 foetid odours emitted from the sewer traps in the streets, an 
 open window is a questionable remedy for bad ventilation. 
 
 We see, then, that there are many causes which render 
 respired air injurious, if made to enter the lungs a second 
 time. In proportion as the air of a confined space becomes 
 vitiated by respiration, the quantity of carbonic acid increases, 
 and as chemistry furnishes the means of determining this 
 increase, while the other noxious products of respiration escape 
 from exact analysis, the amount of carbonic acid may be taken 
 as the exponent of the degree of vitiation of the confined air. 
 This method was adopted a few years ago, by M. Felix Leblanc, 
 in an extensive series of experiments.* 
 
 In conclusion, the writer wishes to state, that if the inventor 
 of any patent warming or ventilating apparatus feels himself 
 neglected in these pages, he may be assured that the omission 
 arises either from want of space, or from want of novelty in 
 the essential details of the invention. It is no compliment to 
 the inventive genius of the present day, to be compelled to 
 state that many of the contrivances, especially for warming, 
 which are put forth as new, and even patented, do not differ 
 in principle from some of those described in old treatises, 
 several of which have been referred to in this work. 
 
 C. T. 
 
 Bedford-place, Ampthill-square, 
 June, 1850. 
 
 * See Memoir read to the Academy of Sciences at Pari^, 6th June, 
 1842, and inserted in the Annales de Chimie et de Physique. Third 
 Series, vol. v. p. 223. 
 
APPENDIX. 
 
 On the principal inventions and improvements that have 
 been made in the Art of Warming and Ven- 
 tilating, between the years 1850 and 1858. 
 
 THE progress that has been made between the years 1850 and 
 1858, in the arts of warming and ventilating buildings must be 
 referred rather to the increased appreciation of the subject on 
 the part of the public, than to the introduction of any important 
 invention, or to the discovery of any new principle. In the 
 preceding pages will be found all that is essential to the success- 
 ful warming and ventilating of buildings ; and what we have 
 now to record are new applications of old principles, new com- 
 binations of old forms, and simplifications of details which are 
 sure to be made when scientific principles have fairly taken 
 root, and begun to operate in men's minds. 
 
 We have, however, to make a correction in the preceding 
 pages, but the interest that attaches to it is purely historical. 
 Its effect, however, is to restore to an old inventor the honour 
 of which he has been most unjustly deprived. At pages 70 to 
 77, the celebrated Polignac f replace, which has served as the 
 type of many modern inventions, is described. Having had 
 to write an article about three years ago on " Warming and 
 Ventilation " for the Quarterly Review, we proceeded to inquire 
 under what circumstances so great a man as the Cardinal 
 Polignac made this useful invention. Mr. Bernan states in his 
 History of Warming and Ventilating Rooms, Sfc., that the 
 Cardinal wrote the description of his fireplace under the 
 assumed name of Ganger, and our description of the fireplace 
 
262 APPENDIX. 
 
 already referred to was taken from Ganger's work. Mr. 
 Bernan opens the second volume of Ms elaborate work in the 
 following manner : 
 
 " The Cardinal Polignac is known as one of the most classic 
 of modern Latin poets ; and his biographers, in their admiration 
 of his nervous versification, profound reasoning, and benevolence 
 of sentiment, place him almost above the great Eoman author 
 whose opinions he combats and overthrows. 
 
 " A small work in a different style of composition, and on a 
 somewhat unpoetical subject, that he composed in 1713, also 
 possesses superlative merit. In this useful treatise the cleric 
 prince observes, that persons who value a machine only from 
 the apparently great effort of genius required to invent it, from 
 the complexity of its parts, the difficulties encountered, and 
 money spent in bringing it into notice, will find little to please 
 their romantic taste in his performance. But those of a more 
 correct judgment, who can see worth in a contrivance notwith- 
 standing its simplicity of construction and easiness of execution, 
 will, perhaps, prefer his apparatus to more ostentatious produc- 
 tions ; and what, for instance, can be more pleasant, useful, 
 economical, and necessary, than to know how to make a fire 
 speedily, and make it burn vividly without the aid of bellows ; 
 to heat a capacious room with a small fire, and at the same time 
 breathe an air fresh and pure, as well as healthily warm ? In 
 Le Mecanique a Feu, he shows how these and other desirable 
 comforts may be obtained by means of a very simple con- 
 trivance." BERNAN, vol. ii., p. 1. 
 
 This statement of Mr. Bernan, repeated by subsequent 
 writers, that the Cardinal de Polignac was the inventor of a new 
 and greatly improved fireplace, and that he described it in a 
 treatise published in 1713, induced us to examine more carefully 
 the original treatise. We met with two copies of the work in 
 the Library of the British Museum, but these were reprints 
 published at Amsterdam in 1714; and on the title page the 
 author's name appeared as " Monsieur ***." We also 
 found in the same library an English translation of the treatise 
 
APPENDIX. 263 
 
 " set forth in French by Monsieur Ganger," published in 1716. 
 We also found in the library of the Eoyal Society a translation, 
 or rather an adaptation of the work by Dr. Desaguliers.* To 
 our surprise the learned doctor gave no hint as to the illustrious 
 authorship of the book, a circumstance altogether unaccountable, 
 if he were aware of it ; for what so likely to make his translation 
 popular, or to favour the introduction of the stoves into 
 England, which appears to have been his intention ? To suppose 
 ignorance in Desaguliers, would be to suppose what is scarcely 
 possible, namely, that so eminent a personage as the Cardinal 
 de Polignac should have caused the stove to be constructed, 
 should have allowed his friends to see it in action, and should 
 have published an elaborate description of it, and yet should be 
 able to prevent the authorship of the treatise from becoming 
 speedily known all over Europe. We next consulted the 
 biographical notices of the Cardinal for information on this 
 point, but in vain ; yet meeting with a passage in Madame de 
 Sevigne's letters, in which she said of Polignac, " II salt tout, 
 il parle de tout, il a toute la douceur, la vivacite, la complaisance, 
 qtfonpeut souhaiter dans le commerce;" the probability again 
 dawned upon us, that if his talents were so versatile, he might, 
 after all, have been the inventor of the fireplace. Accordingly, 
 we waded through a more copious life of the Cardinal, written 
 by Pere Faucher, and published in two volumes in 1780. This 
 work supplied us with much that was amusing and interesting : 
 it described its hero as an orator, a poet, a diplomatist, an anti- 
 quarian, and what was more to the purpose, as a cultivator of 
 
 * " FIRES IMPROV'D : Being a New Method of Building Chimneys, so as 
 to prevent their Smoking : in which A Small Fire shall warm a Room 
 better than a much Larger made the Common Way. With the manner of 
 altering such Chimneys as are already Built, so that they shall perform 
 the same effects. Illustrated with Cuts. Written in French, by Monsieur 
 Gauger : made English, and Improved, by J. T. Desaguliers, M. A., F.R.S. 
 By whom is added, The Manner of making COAL-FIRES, as useful this 
 New- Way, as the WOOD FIRES propos'd by the French Author. Ex- 
 plain'd by an additional Plate. The whole being suited to the Capacity 
 of the meanest Workman." London. 1715. 
 
 N 2 
 
264: APPENDIX. 
 
 the arts and sciences, but still not a word about the fireplace. 
 Again, knowing that Dr. Franklin had taken this so-called 
 Polignac fireplace as the basis of his improved Pennsylvanian 
 stove, we consulted Dr. Franklin's works, and found him more 
 than once referring to these stoves as the invention of a 
 Monsieur Ganger, and not once ascribing them to the Cardinal. 
 Anxious, if possible, to see the Paris editions of the treatise 
 ascribed to Polignac, we repaired to the Library of the Royal 
 Society, where we found the edition published at Paris in 1749, 
 with the name of the author, M. Gauger, honestly looking us in 
 the face. It then occurred to us, what if after all, Gauger 
 should have been a real personage, and not a mere nom de 
 guerre. Impressed with this idea, we consulted the Biographic 
 Universelle, and in the sixteenth volume, published in 1816, 
 we found the following entry, " GAUGEE (NICHOLAS)," pre- 
 facing a notice of his life by M. Pataud, a few points of which 
 it is of importance to state. 
 
 " Nicholas Gauger was born near Pithiviers, about the year 
 1680. He early devoted himself to the study of experimental 
 philosophy, and supported himself by giving experimental 
 lectures in Paris. His character and acquirements gained him 
 the friendship of P. Desmolets of the Oratoire, and of the 
 Chevalier de Louville. The latter said that Gauger, in repeating 
 the experiments of Newton, arrived at more certain results than 
 any of his competitors. Gauger died in 1730, after having 
 published a work entitled ' Mecanique du Feu, ou VArt a" en 
 augmenter les effets, et a" en diminuer la defense.' The first part 
 of this work contained the Traite des nouvelles Cheminees qui 
 echauffent plus que les cheminees ordinaires, et qui ne sont point 
 sujetes afumer. Paris, 1713, 1749, in 12mo., embellished with 
 twelve plates. This work has been often reprinted, and trans- 
 lated into different languages, and includes a great part of the 
 inventions of this description which have since been published 
 as new. It contains an account of those healthful fireplaces and 
 stoves in which there is a double current of air, invented by the 
 same author, and described in the Collection des Machines of the 
 
APPENDIX. 265 
 
 Academy of Sciences for the year 1720, Nos. 218 to 222. 
 Ganger's process having been followed for the first time by his 
 brother, a Chartreux monk, the fireplaces made after that prin- 
 ciple came to be called fireplaces a la Chartreuse" We learn 
 from the same memoir that in 1728, Ganger published an essay 
 on the refrangibility of the rays of light, and also an answer to 
 the objections to Newton's Theory of the Composition of White 
 Light. It appears from the title-page r of an essay on Ther- 
 mometers and Barometers, published in 1722, that Ganger 
 was "Avocat au Parlement de Paris, et Censure Boy ale des 
 livres." 
 
 With this evidence before us, and more to which we shall 
 presently refer, we returned once more to the consideration of 
 Mr. Bernan's work, and found that he continued in the same 
 strain as the extract above given, to describe through fourteen 
 pages "the Cardinal's" invention, and to give us "the Car- 
 dinal's " thoughts on the matter in " a style of composition " 
 unlike enough to the polished diction of Polignac. He re- 
 peatedly ascribes the authorship of Le Mecanique a Feu, as he 
 persists in calling La Mecanique du Feu to Cardinal Polignac ; 
 in one place saying patronisingly " In his meritorious treatise, 
 the Cardinal delineates several complex varieties of his fireplace." 
 Vol II. p. 6. In another, in " Le Mecanique a leu" the Car- 
 dinal describes one "arrangement of his fireplace with the cali- 
 ducts or meanders perpendicular," &c., p. 7. "This arrangement 
 was deservedly recommended by the Cardinal as the best of the 
 series described in his treatise," p. 11. " And the whole 
 arrangement, continues the Cardinal, is so simple, so conve- 
 nient, and easy of execution, that it is best adapted for general 
 use, and c I myself at this moment apply it to very good pur- 
 pose.'" p. 12. "In the course of his experience the Cardinal 
 found that his fireplace was a perfect specific against the annoy- 
 ance of smoke in rooms, which destroyed the lungs of those who 
 breathed it, and smutched the finishings of the walls, furniture 
 arid everything in the apartment, 'and particularly the lace, 
 linen, skin, and eyes of ladies.' " p. 14. Mr. Benian went a 
 
266 APPENDIX. 
 
 step too far for the most credulous of readers when he ascribed 
 to Polignac, the most polished gentleman and finished orator of 
 his age, any term which could be translated into the "smutched 
 eyes " of ladies. At p. 119 he returns to the subject, and says 
 that " Cardinal Polignac attempted to reflect the radiant heat 
 into the room from parabolic covings." 
 
 Could we suppose that Mr. Bernan's statements were made in 
 ignorance, or that they had arisen from some unaccountable 
 blunder, or from a too credulous following of previous writers, 
 we might be disposed to pardon, while we must continue to 
 deplore, an error which has led others astray. But when we 
 observe that he has consulted all the authorities where the truth 
 stands plainly revealed, that he has consulted Desaguliers' 
 translation of Ganger's work, that he quotes from the " Experi- 
 mental philosophy" of Desaguliers, and even fron the very same 
 postscript in which the Doctor says, " In the year 1715 I trans- 
 lated from the French a book called La Mecanique du Feu, which I 
 knew to be written by Monsieur Ganger, a very ingenious gentle- 
 man of Paris, though he concealed his name ; " * when we find 
 that Mr. Bernan is aware of the engravings of G auger's fireplace 
 in the Memoirs of the French Academy of Sciences for 1720, 
 where the invention is fully described and imputed to its rightful 
 author, and where the question of the printed treatise is not 
 left doubtful, but is thus noticed : " M. Gauger a fait un Traite 
 sur cette matiere, intitule La Mecanique du Feu ou il s' etend 
 beaucoup sur cette sortede cheminees, &c.,"f when we find, more- 
 over, that Mr. Bernan has consulted Dr. Franklin's writings, where, 
 in a list of fireplaces, mention is twice made of these of Gauger, 
 and reference made to M. Ganger's tract, entitled La Mecanique du 
 Feu" % when all these things are considered, with a knowledge 
 
 * Desaguliers' Experimental Philosophy, vol. ii. p. 557. London, 1763. 
 
 f Machines et Inventions approuvees par IS Academic Roy ale des 
 Sciences. Tome quatrieme. Depuis 1720, jusqu' 1726. Published at 
 Paris, 1735. 
 
 J " The Works of Benjamin Franklin." By Jared Sparks. Boston, 
 1840. Vol. vi. pp. 38 and 41. 
 
APPENDIX. 267 
 
 of the fact that both Gauger's Life in the Biographie Universelle* 
 and Polignac's Memoirs by Faucher f were as open to Mr. 
 Bernan as they are to us, and that while in the latter there is 
 not a syllable of any such invention being attributed or attri- 
 butable to the Cardinal, in the former there is a distinct mention 
 of Gauger's inventions, with the full title of the book which 
 describes them (Mecanique du Feu, &c.), a notice of the parts 
 into which the work was divided, its success, and translation 
 into other languages, &c., considering this, we must say that 
 Mr. Bernan has committed one of the most unaccountable 
 blunders which has come under our notice for many a day. 
 
 Having thus restored to its rightful owner the honour of this 
 meritorious invention, we proceed to the more immediate objects 
 of the present brief appendix. During the last seven or eight 
 years there has been an active crusade against the smoke of 
 London, resulting in an Act of Parliament requiring manufac- 
 turers, brewers, &c., so to arrange their furnace fires that no 
 visible smoke shall be discharged into the air, in default of 
 which the owners are subject to pecuniary penalties. This 
 enactment has led to the increased employment of old smoke - 
 consuming apparatus and the invention of new, and although 
 the Act does not of course extend to private dwelling-houses, it 
 has had some effect in directing the public mind to the question 
 whether all grates may not be made smoke-consuming. We have 
 seen (page 78) how Dr. Franklin contrived to get rid of visible 
 smoke, and attempts have been made to effect the same object 
 by feeding the fire from below, so that the smoke in passing 
 through the incandescent fuel should be consumed. In Cutler's 
 arrangement, a box filled with coal was placed under the fire ; 
 the box had a moveable bottom resting on a cross-bar of iron, 
 by raising which the coal was gradually lifted into the grate. 
 The bar in rising was guided by slits in the side of the coal-box, 
 and was lifted by chains at each end, drawn up by a windlass. 
 
 * Biographic Universelle. Tome xvi. pp. 576, 577. 
 
 f Histoire du Cardinal de Polignac. By Pere Faucher, Paris, 1780. 
 
268 
 
 APPENDIX. 
 
 
 This arrangement failed, apparently for want of simplicity and 
 economy. Dr. Arnott has effected the same object by simpler 
 means in an invention which he calls " The Smokeless Fireplace ;" 
 this is described by him in a work* from which we gather the 
 following particulars : 
 
 Fig. 88 shows the arrangements of this fireplace. The fire- 
 box e, f, g, k, containing the charge of coal for the day's con- 
 sumption has a moveable false bot- 
 tom or piston s, s, supported by a 
 piston-rod m, n, furnished with 
 notches in which the catch i, u, 
 engages so as to support the piston 
 at any required height. By placing 
 the poker in one of these notches, 
 and resting its point on some fixed 
 support, it may be used as a 
 lever of the second kind for raising 
 the piston, and bringing a fresh 
 supply of fuel into the grate. 
 Should it be required to replenish 
 the coal-box while the fire is burn- 
 ing, as when the piston is on a 
 level with the bottom bar of the 
 grate e, /, a broad jflat shovel or 
 IH"."."III"_"1X".7 spade of the shape of the bot- 
 Fi - 88 - torn of the grate is pushed in over 
 
 the piston, which being let down to the bottom of the coal- 
 box, the spade is raised in front by its handle, when the two front 
 bars 'of the grate, yielding upwards to the pressure expose the 
 mouth of the coal-box and a new charge of coal being shot in, the 
 fire goes on burning as before. In lighting the fire the wood is laid 
 on the upper surface of the fresh coal in the box, with a thick- 
 ness of 3 or 4 inches of cinder or coked coal from the fire of the 
 
 * On the Smokeless Fireplace, Chimney-valves, and other means, 
 old and new, of obtaining healthful Warmth and Ventilation." By 
 Neil Arnott, M.D., F.R.S., &c. London, 1855. 
 
APPENDIX. 269 
 
 preceding day, when the wood being lighted ignites the cinder 
 above, and distils some of the pitchy vapour from the fresh coal 
 below, and rising through the wood, flame, and cinders, burns 
 with a flame. When the cinder is fairly ignited, the volatile 
 portions of the coal, passing through the fire, will be decom- 
 posed and resolved into invisible products of combustion, and 
 the fire will remain smokeless. Of course it is not necessary 
 to let the fire go out every day. If the coal-box be filled once 
 or twice a day according to the requirements of the grate, it will 
 go on smouldering during the hours of the night, and can be 
 quickly brought into full activity in the morning by raising the 
 piston rod. It is a point of importance that the piston shall fit 
 accurately in the box to prevent the ingress of air from below, 
 or in other words, to limit the combustion to that part of the 
 fire which is visible from the room. If, however, it is required 
 that the fire shall give out heat during the night, a small opening 
 is made at the bottom of the coal-box for the admission of air, 
 so that the combustion may be somewhat quickened. This 
 opening also admits of enlargement for the purpose of removing 
 the coal dust and ashes before lighting the fire. 
 
 We are not able from personal experience to speak of the 
 success of this grate ; we have seen it in action, and think well 
 of it.* Its success as a smoke consumer must depend on the 
 
 * A scientific friend writes to us of this stove as follows: " It is 
 rather troublesome to manage, because I keep it going night and day in 
 the winter time ; but I find the comfort of it to be well worth the 
 trouble, as the room is warm in the morning, and I have merely to 
 work the piston up 2 or 3 pegs, and get into bed again ; the fire then 
 burns up of itself. In the day time it is allowed to smoulder in the 
 box, and is worked up a little at night. It burns one small scuttle-full 
 of coals in 24 hours in cold weather, and when only just kept alight it 
 has gone for 48 hours with one scuttle-full, which just fills the box of 
 the stove. It is a great acquisition for a person with delicate lungs. 
 The chief trouble is in filling the box while the fire is alight. If, how- 
 ever, the fire is allowed to go out, and is lit again each day or night, 
 there is not much trouble with it ; in fact less than with an ordinary 
 fireplace, if we reckon the trouble of stirring and putting on coals at 
 
 N 3 
 
270 APPENDIX. 
 
 proper action of the piston and ratchet bar : we have heard of 
 one or two cases where the piston has become fixed by a foreign 
 body such as a nail in the coal, and also by the fusion of 
 matters in the coal : the ratchet-catch and bar may now and 
 then get out of order, but the chief source of failure in this 
 grate is the impatience which servants display on having to 
 raise the fire so as to feed it from below. With them, the 
 quickest and most natural method of feeding a fire is by dis- 
 charging upon it an avalanche of coals from the scuttle. We 
 have known even the mistress herself thus convert the smokeless 
 fireplace into an eminently smoky one. Besides, we are not 
 sure that the so-called "combustion of smoke" produces so 
 many advantages as the public suppose. It is true that the 
 smoky atmosphere of London entails great labour and expense 
 on its inhabitants in maintaining cleanliness. Dr. Arnott states 
 that the cost of washing the clothes of its inhabitants is greater 
 by 2i million pounds sterling a year than for the same number 
 of families resident in the country, to say nothing of the injury 
 of such articles as carpets and curtains, female apparel, books 
 and paintings, decorations of walls and ceilings, and even the 
 stones and bricks of the houses themselves from the same cause. 
 Then again, the frequent washing of hands and face leads to an 
 increased consumption of soap. Many flowering shrubs and 
 trees either cannot live or do not thrive in a London atmosphere. 
 These and many similar charges have been brought against the 
 smoke of London, by which is meant that portion of the fuel 
 which has escaped combustion and is discharged from chimneys 
 in a minutely divided form, constituting the soot or visible 
 smoke of a coal fire. The combustion of smoke, in its truest 
 sense, can only get rid of this visible portion of the products of 
 combustion, which is so obvious as to offend the eye, and con- 
 taminate the houses and their inhabitants. We cannot however 
 agree with those who imagine that by getting rid of the visible 
 
 intervals during the day. The keeping-alight-all-night-without-touching 
 property, is what I bought it for." 
 
APPENDIX. 271 
 
 carbon, we should greatly improve the health of the metropolis. 
 Smoke is really a complicated product ; the coal which is burnt 
 in an open fire resolves itself into carbonic acid and water far 
 greater in weight than the weight of the fuel originally burnt, 
 together with small quantities of ammonia and sulphurous acid, 
 flakes of pitchy bituminous matter, soot, dust, and ashes. Some 
 injury is no doubt caused by inhaling the soot ; but by passing 
 the smoke through the fire or setting in operation some smoke- 
 consuming apparatus, we convert the visible into an invisible 
 smoke, cleaner it is true, but scarcely more wholesome than the 
 murky cloud which hangs over our city. We increase the 
 quantity of carbonic acid and do not get rid of the sulphur com- 
 pounds, and it is these latter which are so inimical to vegetable 
 life, and prevent the growth of that minute vegetation on the 
 surfaces of stone buildings which, while clothing them in 
 picturesque tints, protects them from the disintegrating effects 
 of the weather. The sulphurous acid has also a directly cor- 
 rosive action on the stone itself, on vegetation, furniture, and 
 most objects that it comes in contact with. 
 
 But Dr. Arnott's fireplace has other merits in addition to that 
 of consuming its own smoke. Under ordinary circumstances, 
 the smoke of an open fire consists, not only of the pure products 
 of combustion, but of the air of the room, which constantly 
 streams into the open space above the fire, mingles with the 
 smoke, dilutes it, and sets in motion the numerous chink 
 draughts which render the open fireplace objectionable. Now 
 the quantity of pure smoke given off by a fire is comparatively 
 small, consisting as it does of the air which actually passes 
 through the fire to maintain the combustion, and the consequent 
 combination of the oxygen of such air with the carbon, 
 hydrogen, &c., of the fuel. The air which streams into the 
 chimney from the room above the fire is a wasteful expenditure 
 of the heat of the fire. To prevent this, Dr. Arnott places over 
 the fire a cover or hood of metal, y, a, b (fig. 88.), or, which he 
 prefers, the space over the fire is similarly contracted by brickwork. 
 The effect of this is, according to him, a saving of from one-third 
 
272 APPENDIX. 
 
 to one-half of the fuel required to maintain the desired 
 temperature. The narrow part of the hood or brick channel 
 is furnished with a throttle valve or damper t, to regulate the 
 current of air which passes into the chimney. This valve should 
 not be opened more than enough to let the transparent smoke 
 pass through. The size of the front opening of the fireplace 
 admits of being contracted by means of a moveable plate or 
 blower, o, p, q, r, so as to be able to raise the fire into activity 
 in a few minutes. By the above arrangements, chink draughts 
 from doors and windows are diminished, and they may be 
 stopped altogether by making a special provision for the supply 
 of air to the fire. This is done by means of the channel k, I, 
 under the floor, leading directly from the external atmosphere 
 to the hearth. The air coming in contact with the hot fender 
 becomes tempered before it spreads into the room, while the 
 products of respiration and of the combustion of lamps and 
 candles are got rid of by means of the balanced valve v, which 
 can be shut or left free to open by regulating the screw at x. 
 
 A skilful combination of the air-tube and caliducts of 
 Ganger's fireplace has been made by Mr. Francis Lloyd, and 
 described by him in the pamphlet mentioned below.* On con- 
 sidering the structure of an ordinary register stove, it occurred 
 to him, that a considerable portion of the hollow space behind 
 it might be turned to useful account, by substituting for the 
 mere shell of cast-iron one horizontal, and two upright tubes or 
 caliducts, and by connecting them with one beneath the hearth- 
 plate to form a continuous tube round the fire, for the purpose 
 of warming the air which passed through it. The air thus 
 warmed was next to be admitted to the room in such a way 
 that the inflowing current should not incommode the occu- 
 pants. The upper part of the mantel seemed well adapted to 
 this purpose, and supposing the upper horizontal tube to have 
 
 * " Practical Remarks on the Warming, Ventilation, and Humidity 
 of Rooms." London, 1854. Mr. Lloyd has also published "A Descrip- 
 tion of Improved Hollow Bricks and Brickwork, intended to facilitate 
 the Ventilation of Rooms." December, 1855. 
 
APPENDIX. 273 
 
 an opening or slit extending along the top, and the stove being 
 set sufficiently forward to place this slit beyond the line of the 
 chimney-breast, the upper mantel, and mantel-shelf, could be 
 formed so as to continue the passage-way from this tube, and 
 thus the warm air would be discharged upwards into the room 
 at about four feet above the level of the floor. The plan was 
 adopted with success in Mr. Lloyd's house in town, and a 
 second, and still more successful experiment, was tried at his 
 country residence : 
 
 " The dining-room of a house, a few miles from town, was 
 rendered scarcely inhabitable in consequence of the chimney 
 smoking. The room (which was about 16 feet square and 8 
 feet high) was on the ground-floor, with no basement-story 
 beneath. It was a few inches below the level of the garden in 
 front, and had a provision for the circulation of air beneath the 
 floor. The house was old, with doors and windows fitting but 
 indifferently. The stove was of modern make; but the fire 
 invariably burnt dull, and the room was scarcely ever well 
 warmed. As the room was required for daily use by the family, 
 alterations to the old stove would have caused inconvenience ; a 
 new register-stove, of the ordinary dining-room kind, was 
 therefore selected, with a view of trying how such an one could 
 be fitted with air-tubes. The plan of the new stove is shown 
 in fig. 89. To the cheeks and the back of the face a a, of the 
 stove, were riveted two strips of sheet-iron, bent in the form 
 
 Fig. 89. Fig, 90. Fig. 91. 
 
 shown in fig. 90. The plan then appeared as in fig. 91. Two 
 side chambers or tubes 5, 5, being thus obtained, the back of 
 the upper face of the stove was fitted with a rectangular tube, 
 also of sheet-iron, which was connected with the two side tubes, 
 making uninterrupted communication between them. The old 
 stove was set very far back in the chimney shaft, and was fitted 
 
274 APPENDIX. 
 
 with a large marble mantel, the displacement or altering of 
 which was on many accounts objectionable ; it was therefore 
 determined, in this instance, to admit the air into the room 
 immediately under the mantelpiece, and afterwards to adopt 
 means for preventing any inconvenient rush of air in a horizontal 
 line into the room. The area of a section of each of the side 
 tubes exceeded 1 8 inches, while that of the horizontal tube was 
 about 40 inches. The width of the face of the stove was three 
 feet ; and to furnish the means for the admission of the air into 
 the room, an opening of one inch in width was left at the top 
 of the horizontal tube, in its vertical face, extending its whole 
 length. A hearth-plate of cast-iron was then provided with 
 openings corresponding to the horizontal section of the side 
 tubes as shown in the plan. The hearth-plate was then set 
 with a chamber beneath, extending in the middle as far back as 
 the line of the front firebars. Prom this chamber, a zinc tube, 
 6 inches square, was carried under the marble hearth, beneath 
 the floor, through the front wall into the garden, where it was 
 carried up to the height of 14 inches, and was furnished with a 
 cap having sides of finely perforated zinc. A passage way of 
 36 inches area was thus obtained beneath, around, and above 
 the front part of the stove, while there was a corresponding 
 ingress for the air from the garden, and egress from the upper 
 part of the stove into the room. The stove was set in the 
 ordinary manner ; and within 24 hours of the removal of the 
 old stove, a fire was lighted in the new one, and the room was 
 in occupation. It was at once evident that the tendency to 
 smoke was remedied, and the fire burnt freely and cheerfully. 
 As it was felt to be an important point to introduce the air into 
 the room in such a direction that its entrance should not be 
 perceptible, the air-opening was furnished with a metal plate 
 bent in such a form as would direct the air-stream towards the 
 ceiling, and also admit of the supply being diminished, or 
 stopped entirely, as might be found desirable. The complete 
 and agreeable change in the character of the air of the room 
 was at once apparent to every one ; and instead of the room 
 
APPENDIX. 275 
 
 being barely habitable in cold weather, it was found to be the 
 most comfortable in the house. This stove was fixed at the 
 latter end of December, 1850, and has been in use for four 
 % winters without the slightest difficulty of management, and 
 with entire satisfaction to the inmates of the house. During 
 the first winter careful observations were made on its action, 
 and the results are in many respects remarkable. Within an 
 hour after the fire is lighted, the air issuing from the air- 
 passages is found to be raised to a comfortable temperature ; 
 and it soon attains a heat of 80, at which it can be maintained 
 during the day with a moderate fire. The highest temperature 
 that has been attained has been 95, whilst the lowest on cold 
 days with only a small fire, has been 70. The result of twenty 
 observations gave the following temperatures : on two occa- 
 sions the temperature was 95 ; the fire was large, and the door 
 of the room was left open, so that the draught through the air- 
 tubes was diminished ; on five occasions the temperature was 
 below 80, averaging 75, the remaining thirteen gave an 
 average of 80. The mean temperature of the room at the 
 level of respiration was 61, while the uniformity was so perfect 
 that thermometers hanging on the three sides of the room 
 rarely exhibited a greater difference than 1, although two 
 of the sides were external walls. As might be expected there 
 was no sensible draught from the door and window. On 
 observing the relative temperatures of the inflowing and general 
 air of the room, it appeared that there must be a regular current 
 from the ceiling down to the lower part of the room, and thence 
 to the fire. The inflowing current being of a temperature 
 nearly approximating to that of the body, was not easily 
 detected by the hand ; but on being tried by the flame of a 
 candle it was observed to be very rapid, and to pursue a course 
 nearly perpendicular towards the top of the room, widening as 
 it ascended. It was also noticed that the odour of dinner was 
 imperceptible in a remarkably short time after the meal was 
 concluded. In order to trace the course of the air with some 
 exactitude, various expedients were made use of. It was felt to 
 
276 APPENDIX. 
 
 be a matter of great interest to ascertain if possible the 
 direction of air respired by the lungs. The smoke of a cigar as 
 discharged from the mouth has probably a temperature about 
 the same as respired air, higher rather than lower, and was 
 therefore assumed to be a satisfactory indicator. On its being 
 repeatedly tried, it was observed that the smoke did not ascend 
 to any great height in the room, but tended to form itself into a 
 filmy cloud at about three feet above the floor, at which level it 
 maintained itself steadily, while it was gently wafted along the 
 room to the fireplace. In order to get an abundant supply of 
 visible smoke of a moderate temperature, a fumigator charged 
 with cut brown paper was used. By this means a dense volume 
 of smoke was obtained in a few seconds ; and it conducted 
 itself as in the last-mentioned experiment. On discharging 
 smoke into the inflowing air -cur rent, it was diffused so rapidly 
 that its course could not be traced, but in a short time no smoke 
 was observable in the room. Another experiment was made 
 with a small balloon, charged with carburetted hydrogen gas, 
 and balanced to the specific gravity of the air. On setting it 
 at liberty near the air-opening it was borne rapidly to the 
 ceiling, near which it floated to one of the sides of the room, 
 according to the part of the current in which it was set free ; 
 it then invariably descended slowly, and made its way with a 
 gentle motion towards the fire. The air has always felt fresh 
 and agreeable, however many continuous hours the room may 
 have been occupied, or however numerous the occupants. It is 
 difficult to estimate the velocity of the inflowing current ; but if 
 it be assumed to be 10 feet per second, there would pass through 
 the air-tubes in 12 minutes as much air as will equal the 
 contents of the room. And as it appears that the air so 
 admitted passes from the room in a continuous horizontal 
 stream, carrying with it up the chimney the rarefied air, the 
 exhalations from the persons present, the vitiated air from the 
 lamps or candles, and all vapours rising from the table, it is by 
 no means surprising that the air should always be refreshing 
 and healthful. Since this stove has been fixed, others have 
 
APPENDIX. 
 
 277 
 
 elsewherere been fitted up on the same principle, and have been 
 found to exhibit similar satisfactory results." 
 
 The tubular stove is shown in vertical and horizontal section 
 at figs. 92 and 93, in which a is a flue 6x9 inches, for con- 
 ducting the external air from the outer wall to the under side of 
 the^hearth-plate b ; c c are openings in the hearth-plate b, com- 
 municating with two upright tubes of similar form, which 
 
 Fig. 92. 
 
 Fig. 93. 
 
 conduct the air entering at a upwards to the horizontal tube d. 
 This tube is fitted to the two upright tubes, and has an opening 
 extending along its whole length. If the width of the stove be 
 37eet, this opening should be 1^ inch wide. The stove should 
 be set 1 J inch forward from the chimney-breast ; / is the upper 
 mantel, standing forward from the chimney-breast e, 1} inch; 
 g is the mantel- shelf, with a portion of the back next the 
 chimney -breast cut away in order to continue the air-passage ; 
 h is a thin slab of marble, l inch deep, built into the chimney- 
 breast, and extending to the width of the mantel ; it serves as a 
 support for a chimney glass, and also to divert the current of 
 air from flowing directly up the chimney-breast ; i is a strip of 
 metal or marble, which serves to guide the air stream upwards. 
 By moving i to h, the supply of air may be regulated ; or i may 
 be fixed, arid a thin strip of metal fixed on centres at the 
 
278 
 
 APPENDIX. 
 
 extremities be placed between i and k, so as to act like a 
 throttle-valve. The opening between i and k need not be more 
 than one inch. 
 
 Mr. Lloyd has also shown how hollow bricks may be 
 employed so as to afford cheap, simple, and effectual means of 
 ventilation, well adapted to the humbler class of dwellings. Fig. 
 94 is a brick of ordinary dimensions, containing two per- 
 forations each about 2 inches square; fig. 95 is a similar brick, 
 with pieces of the sides cut away, and fig. 96 is an arrangement 
 
 Fig. 94. 
 
 Fig. 95. 
 
 of these bricks, in which the dotted lines mark air-channels 
 intended for the back of the fire-place and chimney-shaft. These 
 air-flues may be carried to any height, and to the right or left 
 as required, so that the heat at the back of the fire-place and of 
 the chimney may be distributed to every room in the house, 
 and maintain a comfortable temperature at the expense of only 
 one fire. The hollow brick shaft being warmed by contact, will 
 retain its heat for a considerable time, and warm the air in the 
 air flues. 
 
 Among the various contrivances for warming private dwellings, 
 the prejudices in favour of the open fire have been respected. 
 Pierce's Pyro-pneumatic Stove-grates retain the open fire : fresh 
 air is introduced from the outside by means of earthen pipes, 
 and passing into caliducts, enters the room at an elevated 
 temperature. The distinguishing feature of the invention is, 
 that the heating surfaces are formed of fire -loam, so that the air 
 
APPENDIX. 
 
 279 
 
 is not burnt by contact with iron. In Jobson's Stove-grate the 
 open fire is surrounded by a circular parabolic reflector, which 
 reflects the rays of light and heat into the room in parallel 
 lines. The reflector turns upon a hinge at the side, and can be 
 brought out like a door for the purpose of cleaning the grate or 
 lighting the fire. There is a concealed ash-pan, which requires 
 to be emptied only once a week. As the parabolic casting 
 surrounds the grate, there is little or no passage for the air into 
 the chimney, .except through or close over the fire ; but the 
 reflector can be made to act as a ventilator by drawing it out an 
 inch or two, so as to allow the air to flow in around it. 
 Griffin's Cottager's Stove appears to be judiciously arranged for 
 the purposes of warming and ventilating. Fig. 97 is an external 
 elevation, and fig. 98 a vertical section. It has an open fire- 
 
 Fig. 97. Fig. 98. 
 
 place in the centre ; a draw-shelf at the bottom of the grate ; a 
 drop-shelf at the top, which forms a blower when raised ; a hot 
 plate for an ironing stove ; an opening at the top for the escape 
 of warm air ; two ovens, or one oven and one hot closet ; also a 
 damper, a sweep-door, and a boiler. In the flange of the oven 
 and closet are side-doors for sweeping when required. The 
 oven is equally heated all round by means of a flue, and when 
 cooking is over, a fire of wet small coal, cinders, and ashes will 
 last for several hours. Air is supplied from without by means 
 
280 APPENDIX. 
 
 of a pipe, which feeds the hot air chambers at the back and side 
 of the fireplace, and it escapes by an opening at the top. Even 
 in the application of gas as a source of in-door warmth, attempts 
 have been made to imitate the open fire. In Mr. Goddard's 
 Gas-stove, the sides fold down so as to form a box of moderate 
 dimensions, capable of being carried from room to room. 
 When required for use; the sides are opened, and a flattened 
 coil burner is supplied with gas by means . of a flexible tube. 
 When not intended to shut up, the fire-chamber is coated 
 internally with porcelain, within which a tubular burner is set 
 at an angle of 45. A quantity of asbestos shavings being 
 spread over the burner, the effect is something like that of a 
 common fire. In Ward's gas-stove the jets burn within a 
 frame of thin sheet iron, which is fitted into an ordinary fire- 
 place, after the manner of a fire-board. 
 
 A good application of Dr. Arnott's Close stove for the purpose 
 of warming and ventilating, has been made by Mr. Charles 
 Cowper. In the back kitchen of his house, which is but little 
 used, he placed an Arnott's Stove, and partially enclosed it in a 
 case of sheet-iron, so as to form a kind of air-jacket, opening 
 into which was a zinc pipe, 5 inches in diameter, the other end 
 passing through the wall into the open air. By this contrivance, 
 all the air entering at the pipe was made to spread itself over 
 the exterior of the stove, and thus become gently warmed. The 
 effect of this arrangement has been to make the house much 
 more comfortable as regards temperature, and to cure the 
 chimneys of their tendency to smoke. 
 
 Passing from these domestic arrangements to the larger and 
 more difficult subject of warming and ventilating public buildings, 
 we may just allude to the methods adopted by Mr. Goldsworthy 
 Gurney at the Palace of Westminster. Some of the details 
 introduced by Dr. Eeid in the temporary House of Commons 
 (described at pp. 213 to 220) have been retained. The fresh 
 air is taken from the courts of the palace, filtered through 
 screens, and, during winter, warmed by being passed over iron 
 boxes or batteries filled with steam. During summer these 
 
APPENDIX. 281 
 
 batteries are covered with wet clothes, and a number of spray 
 jets, formed by causing jets of water to play against small disks 
 of metal, which spread the water into filmy sheets, cool down 
 the entering air by evaporation, and charge it with the requisite 
 amount of moisture. These batteries and spray jets are 
 arranged in mixing chambers, situated immediately under the 
 floors of either House, and the air thus prepared streams into the 
 House through the perforated floor, formed of iron grating,' the 
 floor of the raised benches being also perforated. The perfora- 
 tions are covered with a porous horsehair cloth or matting, 
 which prevents the upward currents from being felt. The force 
 which sets these currents in motion is an enormous coke fire, 
 maintained in one case in one of the buttresses of the Victoria 
 Tower which is made hollow for the purpose, and in the other 
 case in a chimney-shaft of considerable dimensions. These fires 
 are connected by means of closed passages with the ceilings of 
 the two houses, through the raised panels of which the vitiated 
 air escapes on its way to maintain the combustion of the coke 
 fires, after the manner shown in Fig. 80, p. 212. In the lower 
 part of the palace is a series of steam boilers, both for high and 
 for low pressure steam, from which proceeds an immense assem- 
 blage of pipes to every part of this vast structure, which serve 
 either as sources of heat or ventilating forces. The condensed 
 water of these pipes is returned to the boilers. 
 
 During the unusually warm weather of the summer of the 
 present year (1858), the Thames has been in a constant state of 
 putrefactive fermentation in consequence of the use to which it 
 is so unwisely applied, namely, that of a common sewer to a 
 city which covers upwards of 150 square miles. The Palace of 
 Westminster, situated on the banks of this pestiferous stream, 
 notwithstanding its elaborate arrangements for ventilation, has 
 during the present session had its supplies of air more than 
 usually contaminated. Mr. Guruey found that the air entering 
 the House of Peers and the House of Commons through the 
 proper ventilating channels could be purified from the river 
 effluvia by means of the spray jets, while the air entering by 
 
282 APPENDIX. 
 
 open windows in the libraries and committee rooms looking 
 towards the river, could be purified by causing it to filter 
 through canvas, moistened with a weak solution of chloride 
 of zinc and chloride of lime, fixed to all the windows. In 
 the month of June, however, the river became so unusually 
 offensive that Mr. Gurney was compelled to report that he 
 could no longer be answerable for the health of the two Houses. 
 Accordingly various other plans were proposed for purifying 
 the air, among which was one by Mr. Charles Cowper, based 
 on Dr. Stenhouse's experiments on the disinfecting powers 
 of charcoal. It had been known from the time of Saussure 
 that freshly burnt box-wood charcoal exerted a remarkable 
 absorptive power on gases, taking up 90 times its own bulk 
 of ammoniacal gas, 85 of hydrochloric acid gas, 65 of 
 sulphurous acid, 55 of sulphuretted hydrogen, 35 of carbonic 
 acid, 9-4 of carbonic oxide, 9 '2 of oxygen, 7*2 of nitrogen, and 
 only 1*7 of hydrogen, an order almost identical with that of the 
 solubility of the same gases in water. The remarkable action of 
 finely divided charcoal on putrescible matter had also been 
 known : animal matter in a high putrefactive state ceases to be 
 offensive when covered with a layer of charcoal : it continues to 
 decay but it emits no fetid odour, the carbon which it evolves is 
 dissipated as carbonic acid, while the hydrogen remains in the form 
 of water, and the nitrogen as nitric acid. The action of the char- 
 coal has been shown by Dr. Stenhouse to consist in a rapid pro- 
 cess of oxidation dependent on its power of condensing oxygen. 
 So efficient and rapid is the action of the charcoal, that Dr. Sten- 
 house proposed to employ a respirator filled with charcoal as a 
 covering to the mouth and nostrils in an infected atmosphere, 
 and to use trays or screens filled with powdered wood charcoal 
 in dissecting rooms, in the wards of hospitals, in water-closets, 
 and in places where putrescent animal matter is present. In all 
 such cases the disinfecting powers of charcoal have been very 
 apparent. Mr. Cowper proposes to have the air for supplying 
 the Houses of Parliament drawn through a large chamber or 
 room filled with sticks of charcoal free from dust, and as a 
 
APPENDIX. 283 
 
 further precaution to draw the air out of the base of the clock 
 tower, keeping all windows and doors shut, so that all the air 
 must enter at the belfry about 200 feet or more above the 
 ground. 
 
 An efficient method of ventilation has been contrived by Mr. 
 E. A. Cowper, for ventilating the General Post Office in St. 
 Martin' s-le- Grand. Air is introduced into the large rooms, 
 kitchens, &c., by means of a main trunk, communicating with 
 the open air at the top of the building, while at the bottom of 
 the main is a large fan* driven by steam power, which forces air 
 through the main at the rate of about 30 feet per second. The 
 air on entering the main is filtered by means of three screens of 
 wire gauze of different sizes, placed vertically with pockets 
 beneath for the reception of solid matter. Some idea may be 
 formed of the amount of solid impurities in the air of London, 
 from the fact that the meshes get choked in the course of a few 
 days, and require to be cleaned with a brush, while in the course 
 of ten days, dirt accumulates in the pockets to the depth of an 
 inch. Three degrees of fineness are used for the wire- gauze, the 
 coarsest containing 12 meshes to the linear inch, the medium 
 size 16 meshes, and the finest 20 meshes. From the main 
 shaft are branch mains proceeding to each room, and in each 
 room are branches connected with them by a certain fixed size 
 of aperture or by valves, so as to supply a certain definite 
 quantity of air in a given time to the room. The air is diffused 
 from the branches by means of holes f inch in diameter. 
 These perforated branches ramify under all the tables, and 
 
 * At page 190, the screw is mentioned as a substitute for the fan in 
 ventilation, and it is stated as an advantage that it requires no power to 
 set it in motion except the ascensive force of the vitiated air. This is 
 not quite correct; for unless driven by power it has no effect, except to 
 retard the ascent of the current of air, just as the small screws, or 
 smoke-jacks, which spin so merrily in kitchen- windows and in bakers' 
 shops are driven by the air, and do not of course assist in the ventila- 
 tion : they may do some service in dispersing the air so as to prevent 
 it from pouring in in a torrent, but this effect may be produced by 
 means of perforated zinc, wire gauze, &c. 
 
284 APPENDIX. 
 
 are placed wherever they are required. In the large room, 
 which is 90 feet long and 50 feet wide, and where 200 people 
 are often assembled, the relief afforded by this arrangement was 
 very remarkable. It may perhaps be supposed that the air 
 streaming into a building from these perforated trunks may 
 produce the unpleasant effect of a draught from every aperture ; 
 but Mr. Cowper finds that when the air enters the main at no 
 greater velocity than 2 feet per second, no draught is felt. 
 This velocity is reduced to about 1^ foot per second in the 
 branches, and so little is this felt that the men cannot tell when 
 the fan is at rest or in motion, except in the former case by the 
 deterioration of the air, which does not happen in the latter. 
 Mr. Cowper's three conditions for successful ventilation are, 1st 
 Let the air enter with small velocity. 2ndly Be sure that 
 it does enter, or in other words, employ a ventilating force such 
 as a fan; and Srdly Give plenty of area, so that enough air 
 may enter at the small velocity mentioned. In a large building 
 the air in the main should be kept under a slight pressure, such 
 as that of -j^ths of an inch of water. The foul air is got rid of 
 by suitable openings, and the products of combustion from the 
 gas are removed by placing a funnel over each gas flame ; the 
 funnel has an opening of 5 inches at the mouth, and is con- 
 nected with a 1^ inch pipe discharging into a chimney or into 
 the outer air. The distance between the top of the lamp glass 
 and the bottom of the funnel should be about 1| inch, so as not 
 to point the flame. It is an advantage to keep the pipe hot, 
 (but not so hot as to melt the solder) in order that the water 
 produced by the combustion of the gas may be kept in the state 
 of vapour. Galvanised iron answers well as the material for 
 these pipes, which of course improve the air of the room by 
 acting as a ventilating force. 
 
 The experiment described at p. 165 (fig. 62) has been the 
 basis of patents for ventilating; that is, an opening made in the 
 roof is fitted with a cylinder of zinc or galvanised iron, and 
 divided by a central diaphragm, with a little shed on the top to 
 keep out the rain. The theory is that the foul air will pass out 
 
APPENDIX. 285 
 
 on one side the diaphragm and the fresh air enter by the other. 
 We do not approve of this method of ventilation, since the cold 
 air entering above, must to a certain extent mingle with and 
 condense the heated products of respiration and combustion, and 
 cause them to descend and contaminate the fresh air. Mr. 
 E. A. Cowper, who has much practical experience in ventilation, 
 has in some cases admitted the principle of introducing fresh air 
 at the same level at which the foul air is allowed to escape ; but 
 his method is less objectionable than that of many other inven- 
 tors. He places a perforated box along each side of the room 
 with a pipe carried up some feet on the outside. The room 
 being supposed to be close in other respects and warmed by the 
 occupants, or by means of steam pipes or otherwise, a current 
 of air sets in down one pipe into the room while another current 
 passes out of the room up the other pipe. The wind blowing on 
 one side of the building, or the sun shining on it sets the current 
 in motion, and when once it is started there is a column of ex- 
 ternal cold air in one pipe, and of warm air from the room in 
 the other pipe. The action is then the same as if the cold air 
 pipe were removed, and the air had direct access to the perfo- 
 rated trunk with which it was connected, while the hot air pipe 
 acts as an aerial sewer for draining off the foul air. Thus as 
 long as the room is warmer than the external air, ventilation will 
 continue, but it may be in either direction according as it is 
 first started. The pipes or chimneys may both be on the same 
 side of the building so as to prevent the current from being ac- 
 celerated by a high wind acting on one pipe, and as the equili- 
 brium is unstable the current is sure to commence. This appa- 
 ratus will not, of course, be of any use unless the air in the room 
 is warmer than the external air. Dr. Arnott also mentions a 
 case in which he got rid of foul air and introduced fresh air at 
 the same level ; this was in the dormitory of the Field Lane 
 Ragged School. Six tubes formed of plank of about a foot 
 square opened from the ceiling into two ventilating shafts by 
 horizontal branches. Three tubes connected with one branch 
 were for the escape of the ascending hot foul breath and exhala- 
 
286 APPENDIX. 
 
 tions, while the other three were for the admission of fresh air, 
 which it was supposed would " subside gently and spread among 
 the sleepers." It was observed that ventilation did not begin im- 
 mediately on the entrance of the crowd, but by arranging a gas 
 lamp so as to discharge its burnt air into the ascending shaft, 
 the interchange of currents immediately commenced. 
 
 One of the objections to ventilating openings is that they 
 occasionally bring down cataracts of cold air instead of allowing 
 the escape of the foul air. Dr. Arnott remedies this by covering 
 the ventilating opening with wire gauze, and stretching over 
 this a curtain of light cloth, called a curtain valve, so that the 
 air may pass from within outwards by pushing forward the light 
 curtain, but air cannot pass in the opposite direction, since the 
 attempt to do so would press the curtain against the gauze and 
 close the passage. Dr. Arnott has greatly simplified and im- 
 proved Dr. Hales's Ventilating Pump, described at pp. 191 
 194, and has fitted it with curtain valves. There is a good 
 application of these valves in the Courts of Law at Westminster, 
 which may be seen by going up the staircase at the back of the 
 first Court into a gallery with windows looking on the roof. 
 The Court has a lantern, some of the side windows of which are 
 removed, and a netting is stretched over each opening. On the 
 outside, across the netting, are placed a number of strips of 
 canvas about four or six inches deep fixed by the upper edge. 
 When the warm air of the court seeks an exit, it lifts these 
 curtain valves and breathes out, but if a cold wind seeks to 
 enter, it shuts the valves down on the netting and thus ex- 
 cludes it. 
 
 Dr. Amott's stove, described pp. Ill 115, has been 
 improved by its inventor in several ways, among which we must 
 mention the furnishing of it with a water-jacket, forming what is 
 called a water-stove. This jacket forms an external case or 
 lining to the stove, and is filled with water, which is heated by 
 the fire within ; thus not only is the surface of the stove a 
 source of heat, but it may distribute its heat to other tubes or 
 vessels filled with water, and the heating surface may be indefi- 
 
APPENDIX. 287 
 
 nitely increased by connecting the pipes with very thin flat 
 boxes of sheet copper filled with water, and set up side by side 
 about half an inch apart, in any convenient place, like so many 
 thin portfolios or books of maps. If the pipes are properly 
 arranged, there will be a circulation of water between these 
 water-leaves as they are called, and the water-clad stove. 
 
 We must also refer to Dr. Arnott's Ventilating Gasometer, 
 worked by water power, by means of which the York County 
 Hospital is ventilated. A cylinder or gasometer is made to 
 move up and down in a circular trough of water, contained with 
 itself in a case, furnished with valves, through which air is 
 alternately admitted and discharged during each ascent and 
 descent of the gasometer, in a manner similar to that of the 
 blowing-machine of an iron blast-furnace. The cylinder is 
 suspended from one end of the beam, and a balance weight at 
 the other end. Connected with the beam is a small piston, 
 working in a barrel, beneath which water is admitted by a pipe 
 connected with a tank of water, sixty feet above. The pressure 
 of this column, acting under the piston, sets the beam in motion, 
 and raises the ventilating cylinder to its highest position. A 
 cock or valve, acted- on by a rod from the beam, then shuts off 
 the column of water, and at the same time opens a way for the 
 escape of the water in the small barrel. The ventilating 
 cylinder, which is heavier than its counterpoise, being thus free 
 to move, descends by its own weight ; the water-cock is then 
 opened by a touch from the rod, and the piston again rises, and 
 produces another oscillation of the beam. The cylinder contains 
 about 125 cubic feet of air, and as this moves up and down 
 eight times per minute, it supplies the Hospital with 2000 feet 
 of fresh air in that time. In cold weather the air is warmed by 
 the self-regulating stove with water-leaves. 
 
 THE END. 
 
 BRADBURY AND EVANS, PRINTERS, WHITEFRIARS. 
 
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