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REPORTS 
 
 FFICEKS OF THE NAVY 
 
 VEXTELA.TINI-; AND COOLI 
 
 SXEGUT1V.E %i ENSIGN 
 
 THE ILLNESS OF PRESIDENT MARFIELD. 
 
 \VA S . 1 1 N (rT 
 
 ^w^^^^^^ 
 
 1882, 
 
REPORTS 
 
 
 OFFICERS OF THE NAVY 
 
 ON 
 
 VENTILATING AND COOLING 
 
 THE 
 
 EXECUTIVE MANSION 
 
 DURING 
 
 THE ILLNESS OF PRESIDENT GARFIELD. 
 
 WASHINGTON: 
 
 GOVERNMENT FEINTING OFFICE. 
 
 1882. 
 
3 
 
 REPORTS 
 
 OF 
 
 OFFICERS OF THE 
 
 ON 
 
 VENTILATING AND COOLING THE EXECUTIVE MANSION DURING 
 THE ILLNESS OF PRESIDENT GARFIELD. 
 
 REPORT OF PROF. SIMON NEWCOMB, U. S. NAVY. 
 
 NAUTICAL ALMANAC OFFICE, 
 
 BUREAU OF NVAIGATION, 
 Washington, D. <?., February 28, 1882. 
 
 SIR : In compliance with your order of the 25th instant, I have the 
 honor to present a report of my conference with the surgeons attending 
 the late President Garfield upon ventilating the President's room with 
 cool air, and of the operations in which I took part in pursuance of that 
 conference. 
 
 On the evening of Saturday, July 9, Dr. Woodward, of the attending 
 surgeons, informed me that a number of plans and machines for cooling 
 the air of the President's chamber had been proposed and several tried, 
 but that none had proved effective. It was therefore desired by the at- 
 tending surgeons that I should examine all the plans, and report in what 
 manner the desired result might best be reached. 
 
 Among a number of plans under trial, only three demanded serious 
 consideration. These were : 
 
 I. A large air compresser, such as is used in the Virginia City silver 
 mines, which was sent on by the Rand Manufacturing Company, of 
 New York, and was being mounted by engineers from the navy-yard, 
 under direction of Mr. Edward B. Dorsey. This machine would un- 
 doubtedly have been effective when once in operation, but several days 
 would be required to get it to work, and it was doubtful whether an 
 engine of sufficient power to drive it could be set up within a reasonable 
 time. As a matter of fact, it was removed in a few days without being 
 tried. 
 
 II. A large ice-box, which had been placed in the Executive office, 
 and was expected to cool the air by a downward current through the 
 ice. As the air could pass through only by descending under the influ- 
 ence of its own gravity it produced no appreciable cooling effect, and 
 had to be dismissed from farther consideration. 
 
 III. A machine devised by Mr. R. S. Jennings, of Baltimore, consist- 
 ing essentially of an iron box 27 inches square by 6 feet long, provided 
 with a great number of thin cotton screens. These screens were kept wet 
 with ice- water percolating from a box of melting ice on the top, and the 
 air was forced through the passages between them by a blower. This 
 machine was operated by a portable engine supplied from the Washington 
 navy-yard. It was, however, necessarily ineffective from the necessity 
 
 3 
 
 437 
 
of melting the ice before the latter could be used in cooling, thus wast- 
 ing- the cooling power to be obtained from the absorbtion of heat by 
 the melting ice. 
 
 A large body of warm air passing between the wet partitions warmed 
 them and probably absorbed moisture from them, without itself becom- 
 ing sufficiently cooled. I was informed by Dr. Woodward that, by clos- 
 ing the doors and windows of the Executive office, a slight cooling effect 
 could be observed with the thermometer, but, as all the air admitted was 
 saturated with moisture, the good effect was neutralized. Besides, when 
 the doors and windows were kept open, as was necessary in the Presi- 
 dent's chamber, no cooling effect could be perceived. 
 
 All the proposed plans being either ineffective or impracticable for 
 the time being, it became necessary to devise a new system. The first 
 step necessary was to ascertain, roughly, how many units of heat per 
 day were to be abstracted from the warm air, and how much ice would 
 have to be exposed and melted in order to abstract this amount of heat. 
 One necessary datum in the calculation was the quantity of cool air 
 required. This datum was supplied by Dr. Woodward who stated that 
 12,000 cubic feet of cool air per hour was desirable. I then made a 
 rough computation of the amount of ice it was necessary that air at the 
 temperature of 95 should melt in order that it might be cooled off and 
 deposit the greater part of its moisture. The principal parts of this 
 calculation were: 1,000 pounds air cooled 50 would warm 270 pounds 
 of water 50, and would therefore melt about 100 pounds of ice per hour. 
 
 The condensation of five grains of aqueous vapor from each cubic 
 foot of air would require the condensation of some 10 pounds per hoar, 
 which would require the melting of some 70 pounds of ice. 
 
 Therefore, making no allowance for waste, about 170 pounds of ice 
 per hour, or, say. two tons per day, would have to be melted by a cur- 
 rent of warm air; allowing for waste, it might be estimated that three 
 or four tons of ice per day must be melted by the air itself. 
 
 The next problem was to determine the amount of ice surface which 
 must be exposed in order to cool the air. This was done by taking a 
 block of ice weighing some 200 pounds, and allowing it to stand over a 
 large tin basin 30 minutes. The amount of water which melted from it was 
 then weighed, and found to be six pounds. Such a block would therefore 
 melt off 288 pounds per day. To melt three tons of ice it was necessary 
 that at least three tons should be kept in contact with the cooling air. 
 
 These conclusions were reached about 1 o'clock on Sunday, July 10. 
 In reaching them, and putting them into a practicable shape^I co-op- 
 erated with Prof. J. W. Powell, Director of the Geological Survey. He 
 and I conjointly devised a large ice box, holding some six tons in all, 
 through which the air might pass in one direction and return in the 
 other. He took the sole charge of its construction, and had it ready 
 next morning. 
 
 A fan blower and transmitting pipes for the air being necessary, Mr. 
 Jennings kindly allowed his apparatus to be connected with the new 
 box, so that the latter was put into effective operation without the ne- 
 cessity of additional machinery. The connection was so made that the 
 air passed first through his box and thence into the ice box. The objec- 
 tion that the air was slightly moistened and therefore injured in passing 
 through his box was obviated by the fact that the latter would also act 
 as an auxiliary in cooling the air, while any excess of moisture would be 
 absorbed by the ice in the large box. 
 
 On Monday, July 11, the air from this apparatus was for the first 
 time admitted into the President's chamber and found to be cool, dry, 
 
ami amply in supply. A serious difficulty was, however, met with at 
 first from the whirr of the engine being distinctly audible in the Presi- 
 dent's chamber, being conducted by the tin tubes through which the air 
 pafiaes. Mr. .Jennings proposed to water jacket the tin pipe, but I sug- 
 il that an easier method of cutting off the sound would be to re- 
 move the tin tube and substitute one of canvas. This was done and the 
 sound entirely ceased. 
 
 Professor Powell next constructed a larger ice-box in a different part 
 of the basement on plans of his own. This new apparatus was also 
 supplied with an independent engine and blower from the navy-yard so 
 as to be worked independently of the other. Being primarily intended 
 to take the place of the 'first in case of accident, it was not connected 
 directly with the President's chamber, but with the adjacent corridor. 
 
 From this point Passed Assistant Engineer AVilliam L. Bailie, IT. S. 
 N., assisted by Passed Assistant Engineers Richard Inch and William 
 S. Moore took charge of the operations, under orders of the department, 
 and my active connection with them terminated. I continued, however, 
 to inspect the working of the machinery, and held myself in constant 
 readiness to render the engineers in charge any assistance which might 
 be in my power. 
 
 The multiplicity of parties who took a more or less active part in pro- 
 posing plans for the object in view being likely to give rise to misap- 
 prehension, it may be proper to say that the work of ventilating the 
 Executive Mansion and the President's chamber with cool air was in all 
 its essential features designed and executed by officers of the Navy and 
 Director Powell, with machinery and assistance supplied by the Navy 
 Department. The most material exception was that a fan blower and 
 several feet of pipe for one of the ice boxes was supplied by Mr. Jennings 
 who assisted in putting the plans into operation. 
 
 It may be added that the mutual relations of the naval engineers, Di- 
 rector Powell, and myself were those of friendly co-operators towards the 
 end which had been set' before us by the President's surgeons. 
 Very respectfully, your obedient servant, 
 
 SIMON NEWCOMB, 
 Professor, United States Nary. 
 
 Hon. W. H. HUNT, 
 
 Secretary of the Awry, Navy Department? 
 
 REPORT OF PASSED ASSISTANT ENGINEERS W. L. BAILIE, R. INCH, AND 
 
 W. S. MOORE, U. 8. N. 
 
 WASHINGTON, D. C., October 31, 1881. 
 
 SIR: AVe respectfully submit the following report as the result of our 
 observation of the operation of the cooling apparatus used at the Exec- 
 utive Mansion during President Garfield's illness: 
 
 There were two systems of cooling apparatus employed, one deliver- 
 ing the cool air directly into the President's room, and the other deliv- 
 ering into the corridor outside of the room. 
 
 Mr. K. S. Jennings, of Baltimore, offered, and had accepted for the 
 purpose of cooling the room occupied by the President, a machine used 
 by him for manufacturing purposes, and which is represented in Plate A. 
 
 This machinjB consisted of a cast-iron box 2' 3" by 2' 3" on the end 
 and 6' 6" long, which contained a number of screens made of terry-cot- 
 ton, stretched over thin iron frames, and placed in the box longitudinally 
 
6 
 
 and vertically and of an inch apart; suspended inside and at the top 
 of the box was a shallow pan made of galvanized iron, which was cor- 
 rugated and perforated at the bottom. On the top of the box was placed 
 a galvanized iron tank of about 134 gallons capacity, which was tilled 
 with granulated ice and salt, composed of 64 parts cracked ice, 3 parts 
 salt, and 33 parts water; this brine was taken from the bottom of the 
 tank through |-inch pipe and delivered into the shallow pan in the top of 
 fche box, through which it percolated, and was distributed over the screens, 
 wetting them and reducing their temperature to that due to the coin- 
 position of the brine. Attached to this apparatus was a 14-inch Sturte- 
 vant blower, which was used to. draw the air into the box, and between 
 the screens, reducing it to a corresponding temperature, and delivering 
 it at any desired point. This apparatus of Mr. Jennings was connected 
 with the heating flue leading to the President's chamber, and the air to 
 the box was supplied from outside through an air duct which passes 
 along the top, and the whole length of the corridor in the basement of 
 the Executive Mansion. 
 
 This cooling machine was soon found to be of insufficient capacity to 
 affect the temperature of the President's room with the windows open, 
 but with the windows and doors closed it would have reduced the air in 
 the room to the desired temperature. As, however, it was required that 
 the windows and doors of the sick chamber be left open, the problem of 
 how to cool the room under those conditions was presented, and the at- 
 tention of certain scientific gentlemen was called to the subject. Mr. 
 Jennings proposed to enlarge the capacity of his apparatus by adding 
 two additional- boxes, of wood, containing the same system of screens, 
 to the circuit of air, and by this enlargement he claimed the desired re- 
 sult would be effected, but in view of the necessity of supplying the cool 
 air as quickly as possible, Prof. Simon Newcomb and Major Powell, of 
 the United States Geodetic Survey, suggested the addition of an ice-box 
 to the Jennings machine, of sufficient capacity to hold the amount of ice 
 necessary to meet the emergency, and by a change of pipe connections 
 requiring the air to pass first through the Jennings machine, and then 
 into the ice-box at the top, and after circulating over the ice to be taken 
 by the blower and forced up into the President's room. These sugges- 
 tions were carried out, and the effect was a rapid and continuous supply 
 of air at about 55 Fahr.^t thfc register in the President's room, giving 
 the air in the room an agreeable temperature during the warm weather 
 which prevailed at the time. This apparatus is represented in Plate A, 
 the notes on the plate indicating its different features. 
 
 Subsequently it was ascertained that when a fresh breeze from the 
 south was blowing directly into the President's room, through tne open 
 windows which faced in that direction, it was impossible to affect the 
 temperature of the room by the small 14-inch blower then in use. It was 
 therefore determined to substitute a 36-inch blower, and reverse the cir- 
 cuit so that the air would pass first through the ice-box, then through 
 the Jennings machine to the blower, thence up to the President's room. 
 By this arrangement the temperature was kept at the desired point dur- 
 ing the extremely hot weather which prevailed on August 13 and 14, which 
 may be regarded as a good test of the efficiency of the apparatus. 
 
 By the first arrangement, represented in Plate A, it was observed that 
 all the air delivered into the President's room did not pass through the 
 Jennings machine, but that a large portion was drawn through the 
 leaks in the ice-box; arrangement in Plate B obviated this difficulty, 
 and assured the passage of the air through the pipes leading from the 
 air-duct and not from the corridor through the leaks, and by extending 
 

 the induction pipe into the box a better distribution of the air over the 
 ice was effected. 
 
 The data taken during the running of this cooling apparatus was in- 
 complete, as those who had constant access to the President's room 
 were too busily occupied to take a systematic series of observations in 
 the room, and it was not until after President Garfield was removed to 
 Elberon that we were able to take the temperatures in the room he occu- 
 pied, and t his was done September 7 and 8, during a run of the apparatus 
 tor twenty consecutive hours, under circumstances as nearly as possible 
 like those which existed during the President's illness at the Executive 
 Mansion, excepting the last hour of the run when the windows and 
 doors were closed. 
 
 The outside temperature during the special trial averaged 84P.9 Fahr., 
 and rimniu'g the engine at an average of 102 revolutions per minute, 
 and forcing 22,799 cubic feet of air into the room per hour, resulted 
 in the reduction of the temperature of the room 5.4 Fahr., and this 
 with one window and door open, and a southerly breeze blowing. 
 Although this was in a measure disappointing, so far as the reduction 
 of temperature was concerned, yet the character of the air was so 
 greatly changed by the reduction of the relative humidity of the air 
 that if was agreeable, and could not have been reduced to a lower degree 
 with impunity had the patient been present. 
 
 We were fold by one of the President's attending physicians that 
 the first effect observed when the cooling machine was started was the 
 change in the character of the air, and, even before a sensible change of 
 temperature occurred, a benefit from the machine was experienced in 
 the dryness of the air in the room, which reduced the temperature of 
 the skin by a more rapid evaporation of the moisture at its surface. 
 This effect is not the least in importance; for, as commonly observed, a 
 warm day is not necessarily an oppressive day, if the relative humidity 
 of the atmosphere is not great. The reduction of the relative humidity 
 of the air in the President's room was obtained by the operation of a 
 well-known law in physics, by which the air is deprived of a percentage 
 of its moisture, which it contains at high temperatures, when that same 
 air is reduced to lower temperatures. 
 
 The capacity for holding moisture, or vapor, by the atmosphere is 
 greater at high than at low temperatures, and is consequently deprived 
 of a part of its moisture when passed over the surfaces of the cooling 
 machine, and this moisture the air cannot regain until it escapes from 
 the system of pipes through which it is conducted ; at the point of its 
 escape, however, as its temperature rises, it claims that percentage of 
 moisture of which it has been deprived in the cooling machine from the 
 surrounding atmosphere. An examination of the accompanying Table 
 A will demonstrate the truth of this law. The data were taken during 
 the twenty hours' trial after President Garfield was removed. The 
 relative humidity of the air outside averaged 60, and that of the air 
 in the President's room after passing through the cooling apparatus 
 averaged 54.3. This shows conclusively that the air of the room gave 
 ui> a l )ai 't of its moisture to supply the loss of moisture to the air enter- 
 ing through the cooling apparatus. What the condition and dryness 
 would have been had the cool air been delivered into a closed room we 
 have no means of ascertaining ; but from the result of this experiment, 
 where the relative humidity of the air in the room was maintained at a 
 lower percentage than that of the air outside, with which it was in com- 
 munication through an open window, it is safe to assert that the relative 
 humidity of the air in a closed room can be maintained at anv desired 
 
8 
 
 point. Charles Hood, in his book on Warming and Ventilation, says: 
 The most healthy state of the atmosphere will be obtained when the 
 dew-point of the air is not less than 10 nor more than 20 Fabr. lower 
 than the temperature of the room. When these limits are exceeded the 
 air will be either too dry or too damp for healthy respiration." Exam- 
 ination of Table A shows the dew-point to average 18.5 lower than 
 the temperature at the center of the room, which proves by Hood to 
 have been the most desirable condition of the atmosphere to maintain. 
 
 In order that the President's room might by no accident be deprived 
 of its supply of cold air, Major Powell devised a second machine, which 
 was constructed by labor and material from the navy-yard, the differ- 
 ence between it and the other apparatus consisting in the arrangement 
 of the compartments of the ice box, as shown in Plate 0, and doing 
 away with the box containing the terry-cotton screens. The ice-box 
 was divided into three compartments, an upper, middle, and lower. 
 The air was first taken through the induction pipe and passed over the 
 ice in the upper compartment, from thence down through rectangular 
 holes into the middle compartment, which it traversed, and was then 
 drawn into the lower compartment, and at the opposite end the air was 
 taken by a 36-inch blower and forced through a drying-box up through 
 a system of pipes to the corridor outside of the President's chamber. 
 
 The peculiar feature of this apparatus was the drying-box, which was 
 placed in the circuit for the purpose of drying the air. This purpose 
 was supposed to be accomplished by cooling the bars of iron contained 
 in the box, by causing a freezing mixture of ice and salt to fall on the 
 ends of the bars, thereby cooling them, and by their low temperature 
 causing the air' to deposit on their surface another portion of its moist- 
 ure, after having been deprived of a certain percentage in the ice-box. 
 The purpose for which the drying-box was intended was not accom- 
 plished, as the bars could not, by the means employed, be reduced to a 
 lower temperature than the air when it entered the box. 
 
 By examining Table B, the data for which were taken at various times 
 as opportunity occurred during the time machine No. 2 was employed, 
 we find that the temperatures taken just before entering the drying-box 
 average 56 Fahr., and those temperatures taken just after the air left 
 the box average 59 Fahr., or 3 higher, showing that no reduction of 
 temperature was effected ; the relative humidity of the air entering was 
 85.8 and increased to 86.2 on leaving the box, or 0.4 greater on leaving 
 than when it entered, and proving the box to be of no use MS a dryer. 
 
 Comparing results at the two ice-boxes, we find the air on leaving 
 ice-box No. 1 to be 40.7 Fahr., and leaving ice-box No. 2 to be 53.5 
 Fahr., by which .we conclude that the arrangement of the box into com- 
 partments, did not produce the best results, and may be* accounted for 
 by the air passing over the top surface of the ice as it lay packed upon 
 the floors of the compartments, and not coming in contact with the other 
 surfaces, while in the other box, which was not divided but contained 
 shelves upon which the ice was packed, a greater surface of the ice was 
 exposed to contact with the circulating currents of air, which was con- 
 sequently more effectually cooled. Deflecting diaphragms might have 
 been used with advantage in box No. 2, so as to cause the air to deflect 
 from the direct course and come in contact with the sides of the ice as 
 well as the top, and thus forcing the cold air resting between the cakes 
 of ice into the circuit. 
 
 The effect of the air delivered by this apparatus at the average rate 
 of 39,217.9 cubic feet per hour, was to keep the air in the corridor at a 
 pleasant temperature, although no observations were taken, excepting 
 
at the point the air issued from the pipe, where the average temperature 
 was 03.6 Fahr. In the effort to complete this apparatus as quickly as 
 possible,' right-angle elbows were used in all the pipe connections; the 
 effect was to produce eddying currents at all the bends, the nature of 
 which was noticed at the point of delivery into the corridor. This elbow 
 was 10 inches in diameter, and the passage of the air through it pro- 
 duced an eddy at the point of delivery, the outer circle of which was four 
 inches in diameter, the vertical diameter extending one inch above, and 
 three, inches inside the elbow, the horizontal diameter touching the inner 
 bend of the elbow. This eddy is represented in plate at N. 
 
 The eddy was due to the^shape of the elbow, allowing a dead space 
 at M, into which the emerging cold air falls. By reason of its being of 
 greater specific gravity than the outer atmosphere, it falls until it is 
 again taken up by the main current of air which causes it to complete 
 the circle. When the elbow was replaced by a curved elbow the eddy 
 disappeared. 
 
 The conditions under which the President's room was cooled pre- 
 cluded all considerations of economy. The experiments, therefore, are 
 without value for the purpose of determining the cost of ice sufficient 
 to keep the President's room at an agreeable temperature under more 
 favorable conditions. The problem as presented was the same as to 
 ascertain the price of coal sufficient to keep the room warm on a cold 
 day with the windows open. 
 
 During the twenty hours' run 8,734 pounds of ice were melted, or 
 436.7 pounds per hour. This at $5 per ton, or one-quarter of a cent per 
 pound, would be $1.09 per hour; or this was the cost necessary to supply 
 1*2,799 cubic feet of air at 50 Fahr. at the register per hour. 
 
 Had time been offered for experiment or had experience suggested a 
 more economical method of cooling the President's room much of the 
 waste of cooling material might have been avoided, as for instance, the 
 water of liquefaction which was allowed to run to waste might have 
 been used as a first cooling medium for the air. 
 
 The experiments were also conducted under circumstances unfavor- 
 able for determining the most accurate results, as the observations 
 would be interrupted at any time the air became too cool for the com- 
 fort of the President, the experiments, being, of course, entirely sec- 
 ondary in consideration ; yet a sufficient number of temperatures were 
 observed to show the value of the cooling apparatus, not only as affect- 
 ing the temperature of the room occupied by the President, but affect- 
 ing the best hygrometric condition of the air in the room. 
 
 A more general system of experiments would be interesting, and 
 would furnish most valuable information as regards the cost as well as- 
 the effects of cooling apparatus. 
 
 Our operations at the Executive Mansion have brought to our notice 
 the great importance of. a proper hygrometric condition of the atmos- 
 phere we breathe and in which we live. Great stress is laid upon the 
 subject by various authorities upon ventilation and warming, and not- 
 withstanding its importance appears to be so fully realized, yet but 
 crude attempts have been made to control the hygrometric condition of 
 the air used in ventilating and warming our houses. In summer, with 
 the windows open, the general condition of the atmosphere outside is 
 maintained inside our houses, but in winter, with windows closed, and 
 the ventilation mostly dependent upon the warm air which has passed 
 through the heaters, the conditions are entirely changed. As, for ex- 
 ample, the temperature of the air outside we will suppose to be 20 
 Fahr.; it is passed through the heaters and delivered into a room where 
 
10 
 
 the temperature is maintained at 70 Fahr. ; supposing the windows to 
 be closed and only leakage sufficient to permit ventilation, we will have 
 in this room air at the temperature of 70, the dew-point of which is not 
 above 20 ; for in the manner our heaters are usually constructed there 
 are no means by which the air can receive moisture after it has left the 
 outside of the house. 
 
 The most healthful condition of the air is found to exist when its rela- 
 tive humidity is from 50 to 70 per cent. In the hypothetical case cited, 
 the relative humidity is as low as 15 per cent., an extreme that must be 
 not only unpleasant but injurious. Of course crude attempts have been 
 made to remedy this evil by urns of water placed over or near the heat- 
 ers, but in most instances even this is wanting. It being necessary that 
 the dew-point should not be less than 20 below the temperature of 
 the room, it may be increased as it enters from the outside by passing 
 it through water at a given temperature, say 55 before entering the 
 furnace, saturating the air and establishing the dew-point at that tem- 
 perature, the relative humidity being 58. 
 
 Our operations at the Executive Mansion have proved that it is pos- 
 sible to place the dew-points, or relative humidity of definite quantities of 
 air, at any desired point, and there is no reason why this hygrometric 
 condition may not be maintained with as much certainty as the amount 
 and temperature of air supplied for proper ventilation and warming. 
 This field of study presents great opportunities for effecting a better 
 condition of the atmosphere of our rooms, and our personal comfort and 
 health may be improved in proportion to our careful observation of the 
 hygrometric condition of air in which we live. Hospitals and public 
 buildings ought to be especially protected from the evil results attend- 
 ing a vitiated condition of the air, and we can see no reason why their 
 atmosphere may not be made comfortable and healthful at all seasons 
 and under all conditions of the outside air. 
 
 Hoping the few results obtained from our experiments may be useful 
 in calling more general attention to this subject, and expressing our 
 thanks to the United States Signal Officer for valuable information and 
 the use of instruments, 
 
 We are, very respectfully, your obedient servants, 
 
 WM. L. BAILIE, 
 Passed Assistant Engineer, U. S. N. 
 
 BIOHAED INCH, 
 Passed Assistant Engineer, U. S. N. 
 
 W. S. MOOEE, 
 
 Passed Assistant Engineer, U+S. y. 
 Engineer in Chief W. H. SHOCK, U. S. N., 
 
 Chief Bureau of Steam Engineering, 
 
 Navy Department, Washington, D. C. 
 
11 
 
 TABLE A. 
 
 Datr and 
 hour. 
 
 S.-pr. 7. 
 188L 
 
 4 p. m 
 
 5 p. m 
 
 6 p. m . . 
 
 7 p. m 
 
 8 p. m 
 
 9 p. m 
 
 10 p. m 
 
 11 p. m . . 
 
 12 mid... 
 1 a. m . . 
 J a. in . . 
 :; a. m . . 
 
 4 a. m . . 
 
 5 a. m .. 
 
 6 a. m 
 
 7 a. m . . 
 
 8 a. m . . 
 
 9 a. m . . 
 
 10 a. m. .. 
 
 11 a. m*. 
 
 30. 040 98 
 30. 030 97 
 30. 020 92. 
 
 30. 050 87. 
 30. 062 87. 
 30. 080 84 
 30. 090 84 
 30. 069 83 
 30. 060 81. 
 30. 064 80 
 
 Outside. 
 
 A. 
 
 B. 
 
 C. 
 
 D. 
 
 
 
 J 
 
 
 
 | 
 
 
 
 f 
 
 
 
 4 
 
 i 
 
 
 
 ^ 
 
 > 
 
 
 - ri 
 
 
 
 .2 
 
 = 
 
 
 
 .3 
 
 'g 
 
 
 
 
 
 "g 
 
 
 
 =. 
 
 '2 
 
 
 ~ 
 
 b 
 
 - 
 
 i 
 
 a 
 
 5 
 
 1 
 
 1 
 
 I 
 
 A 
 I 
 
 I 
 
 4 
 
 S, 
 
 1 
 
 S3 
 
 A 
 
 i 
 
 i 
 
 1 
 
 1 
 
 1 
 
 A 
 1 
 
 
 
 P 
 
 1 
 
 3 
 
 98 
 
 76 
 
 64 
 
 34 
 
 83.5 
 
 71.:. 
 
 64 
 
 53 
 
 38 
 
 38 
 
 38 
 
 100 
 
 47.5 
 
 42 
 
 34 
 
 61 
 
 52 
 
 62 
 
 97 
 
 76 65 
 
 35 84 72 65 
 
 53 '39 38 
 
 36 
 
 89 
 
 43 
 
 43 
 
 43 
 
 100 
 
 50 
 
 58 
 
 92.5 
 
 76 68 
 
 46 85 73 66 
 
 53 |40 39 37 89 
 
 42 
 
 42 
 
 42 
 
 100 149* 
 
 57 
 
 89 
 
 76 69 
 
 52 86 74 68 55 i39 38.537 92 
 
 42 42 i42 
 
 100 49 
 
 
 87.5 
 
 77 72 61 86 |76 71 61 39 
 
 38 36 89 
 
 41.541 41 
 
 95 49 
 
 56 
 
 87. 5 77. 5 72 
 
 72 86. 5 ! 73 66 51 39 
 
 38. 5 37 92 J42 
 
 41 40 
 
 92 48. 5 55 
 
 84. 5 76 72 
 
 67 86.573 66 51 39 
 
 38. 5 37 92 41 
 
 41 41 
 
 100 48.555 
 
 84 
 
 7G 72 67 87 ,75 69 55 39 38.537 92 41 41 41 
 
 100 48. 5 54 
 
 30. 080 78 
 30. 085 77 
 30. 100 77 
 30. 115 78 
 30. 125 81 
 30. 135 84 
 30. 130 90 
 30. 134 90 
 
 74 69 
 5 74 70 
 
 71.566 
 572 |68 
 
 j71 167 
 71 68 
 70 ! 66 
 70. 5 65 
 7'J (i7 
 73. 5 67 
 7:. r,7 
 
 75 67 
 
 Averagest 84. 6 73. 
 
 70 87. 5 T:. 
 
 62 86 J73.566 
 
 69 86. 57:i 
 
 141 41 41 
 
 42 42 42 
 
 42 42 42 
 
 42 42 ! 42 
 
 47 
 4S 
 
 48 154 
 
 41. 5 41. 5 41. 5 100 |47. 5 54 
 41. 5 41. 5 41. 5 100 
 |41 (41 41 100 
 
 100 
 
 LOO 
 
 ,42 J42 42 100 
 42 41.541.5 95 
 '43 42 J41 | 92 
 ;43 J43 41! 100 
 43. 5 43. 5 43. 5 100 
 
 4S 
 48 
 48 
 49 
 
 ,50 
 43 43 ;43 ilOO 51 
 
 60 85 73.366.251.940.539 
 
 37. 3 90. 7 42. 3 41. 8 41. 3 96. 5 48. 8 55. 1 
 I I I I I I I . I 
 
 l);it<- and hour. 
 
 Temperatures. 
 
 Center of room. 
 
 g ii 
 
 ! 
 
 Box of the Jen- 
 niiigs machine. 
 
 P 
 
 P 
 
 P P 
 
 o 
 
 t 
 
 > 
 
 fi 
 
 4 
 
 
 Sept. 7, 1881. 
 4 p. m 89. 
 5 p. m 82 
 
 r. 7J til 39 
 72 6fi :.u 
 70 62 48 
 70 62 48 
 68 60 49 
 70 63 54 
 67 58 47 
 67. 5 59 51 
 66 58 51 
 67 60 54 
 67 60 54 
 '67 60 54 
 J68 62 58 
 5 68. 5 62 58 
 569 64 63 
 68 62 58 
 5 68. 5 62 64 
 5:68 62 60 
 567 60 64 
 63 55 51 
 
 ' 
 
 
 
 300 
 75 
 95 
 240 
 
 
 
 
 9 
 - 96 
 95 
 96 
 73 
 
 105 
 130 
 165 
 100 
 66 
 
 100 
 100 
 100 
 100 
 103 
 100 
 100 
 107 
 108 
 105 
 108 
 102 
 99 
 102 
 102 
 102 
 102 
 102 
 102 
 102 
 
 4807520 
 4900360 
 5013218 
 5122266 
 5217960 
 5316300 
 5406438 
 5517798 
 5623552 
 
 790 
 
 20 
 
 120 
 
 
 
 
 
 
 
 
 
 
 7pm 83 
 
 
 
 
 
 
 
 8 p. m 81 
 
 
 
 
 
 
 
 9pm 81 
 
 59 
 57 
 56 
 56.5 
 57 
 56 
 56 
 
 56 
 56 
 57 
 56 
 
 53. 5'47 
 51 4.". 
 52 48 
 52 48 
 52 47 
 51 46 
 51 46 
 51 46 
 51 46 
 51 46 
 51 45 
 51 46 
 
 65 
 64 
 74 
 74 
 69 
 69 
 69 
 69 
 69 
 69 
 64 
 69 
 
 
 
 
 10 p m 80 
 
 
 
 
 11 p m 79 
 
 
 
 
 Y2 midnight 78 
 
 
 
 
 1 a. m 78 
 
 372 
 
 14 
 
 100 
 
 J a. in 78 
 
 5822144 
 
 3 a. in 78 
 
 
 
 
 4 a. m 78 
 
 6019572 
 
 
 
 
 5 a. m 78 
 
 
 
 
 
 6226380 
 6325740 
 6417348 
 6510690 
 6601538 
 6701340 
 
 
 
 
 7 a . 1 1 1 ...... 78 
 
 200 
 
 14 
 
 80 
 
 8 a m 77 
 
 9a.m 77. 
 10 a m 77 
 
 
 
 
 57 
 
 58 
 
 52 
 52 
 
 47 
 46 
 
 69 
 64 
 
 
 
 
 11 a. m* 74 
 
 
 
 
 
 
 
 
 Averagest .... 79. 7 68. 4 61. 2 54. 3 56. 5 51. 5 46. 3 68. 3 
 
 
 
 
 
 
 
 
 
 
 
 
 
 * Window and door closed. 
 
 t For the 19 hours with window and door open. 
 
12 
 
 TABLE B. 
 
 Date and hour. 
 
 Barometer corrected for 
 temperature, e 1 ev a- 
 tion, and instrument 
 error. 
 
 Temperatures. 
 
 Outside. 
 
 Induction pie of blower. 
 
 t>S 
 
 g 
 
 t 
 
 Dew point. 
 
 I 
 I 
 
 
 
 n 
 
 1 
 
 Dew point. 
 
 a 
 
 a 
 
 ^ 
 
 1 
 
 
 29. 791 
 
 .746 
 .725 
 .802 
 .789 
 .780 
 .741 
 .736 
 .824 
 .779 
 .895 
 .867 
 .913 
 .873 
 .907 
 30. 122 
 
 .on 
 
 29. 934 
 .923 
 .863 
 .876 
 / .760 
 .736 
 .755 
 .710 
 
 83 
 84 
 81 
 78 
 75 
 77 
 83 
 81 
 73 
 78 
 87 
 83 
 84 
 87 
 78 
 86 
 90 
 95 
 80 
 83 
 87 
 90 
 91 
 90 
 96 
 
 73 
 71 
 
 70 
 72 
 71 
 72 
 75 
 74 
 68 
 76 
 75 
 72 
 72 
 73 
 69 
 75.5 
 76.5 
 76 
 74 - 
 73 
 76 
 75 
 75 
 76 
 78 
 
 68 
 63 
 67 
 69 
 69 
 69 
 71 
 70 
 65 
 75 
 69 
 66 
 65 
 65 
 64 
 69 
 69 
 66 
 71 
 68 
 70 
 67 
 66 
 69 
 69 
 
 61 
 
 49 
 62 
 74 
 82 
 76 
 67 
 69 
 76 
 91 
 55 
 57 
 53 
 48 
 62 
 57 
 50 
 40 
 74 
 61 
 57 
 47 
 . 44 
 50 
 41 
 
 53 
 
 47 
 47 
 50 
 50 
 60 
 58 
 46 
 47 
 
 11 
 
 45 
 52 
 48.5 
 54 
 51.3 
 73.5 
 65 
 55 
 56 
 56 
 49 
 48 
 64 
 67 
 
 53 
 46 
 46 
 48 
 49 
 57 
 58 
 
 9 
 
 
 
 44 
 50 
 
 47 
 52 
 51 
 70.5 
 62 
 54 
 55. 5 
 55 
 48 
 47.5 
 6.'{ 
 66 
 
 53 
 
 45 
 45 
 46 
 48 
 54 
 58 
 
 8 
 
 11 
 
 43 
 48 
 
 3 
 
 11 
 
 60 
 53 
 56 
 54 
 47 
 48 
 62 
 65 
 
 100 
 93 
 93 
 86 
 93 
 81 
 100 
 93 
 100 
 93 
 100 
 93 
 86 
 93 
 86 
 100 
 84 
 84 
 93 
 97 
 93 
 93 
 97 
 93 
 93 
 
 July 17* 3p m - - 
 
 
 
 
 July 21 11am 
 
 
 July#Jl' 7pm 
 
 July 22' 7 a. m .... -. 
 
 July 22 11 a m 
 
 
 
 July 26 11 am 
 
 July 26 3p m 
 
 July 27 11 a m . 
 
 August 4 11 am 
 
 
 August 63pm 
 
 
 
 August 9 3 p. m ' 
 
 August 10 1*2 m 
 
 August 10 3 p. m 
 
 August 13, 11 a. m 
 
 August 13' 3pm 
 
 Averages 
 
 
 84 
 
 73.5 
 
 68 
 
 59. 7J 53.5 
 
 -9 o 
 
 50 
 
 90 
 
 
 
 
 Date and hour. 
 
 Temperatures. 
 
 At box before entering. 
 
 At box after leaving. 
 
 Corridor. 
 
 a 
 
 3 
 
 .3 
 1 
 
 jj> 
 
 Q 
 
 -^ 
 e 
 
 -R 
 
 A 
 
 , 
 
 1 
 
 a 
 
 3 
 A . 
 
 1 
 
 j? 
 
 56.5 
 53 
 53 
 51.5 
 54 
 60 
 62 
 52 
 51 
 52 
 55 
 52 
 55 
 56 
 57 
 56.5 
 73 
 73 
 64 
 64 
 63 
 62 
 60 
 68 
 70 
 
 i 
 
 * 
 
 1 
 
 'I 
 
 1 
 
 I 
 
 2 
 
 ' - 
 
 a 
 
 1 
 t J 1 , J 
 
 July 17, lla.m 
 July 17 3 p. m 
 
 56 
 53 
 53 
 51 
 53 
 ' 58 
 61 
 47 
 49 
 49 
 53 
 48 
 53 
 51 
 55 
 54 
 75 
 69 
 58 
 59 
 50 
 53 
 52 
 66 
 68 
 
 54 
 48 
 48 
 49 
 49 
 56 
 60 
 45 
 48 
 48 
 51 
 46 
 51 
 48 
 53.5 
 53 
 71 
 66 
 56 
 57.5 
 57 
 51 
 51 
 65 
 66 
 
 52 
 42 
 42 
 47 
 44 
 54 
 59 
 43 
 47 
 47 
 49 
 44 
 49 
 45 
 52 
 52 
 69 
 64 
 54 
 58 
 55 
 49 
 50 
 64 
 65 
 
 86 
 66 
 66 
 86 
 72 
 87 
 93 
 86 
 97 
 97 
 86 
 86 
 86 
 80 
 90 
 93 
 82 
 84 
 87 
 96 
 87 
 86 
 93 
 94 
 90 
 
 55 
 52 
 51 
 51 
 53 
 57 
 61 
 51 
 50 
 50 
 53 
 50 
 52.5 
 51 
 54 
 54 
 71 
 71 
 61 
 61.5 
 59 
 59 
 57 
 66 
 67 
 
 55.5 
 51 
 49 
 51 
 52 
 54 
 60 
 50 
 49 
 48 
 51 
 48 
 50 
 46 
 51 
 53 
 70 
 70 
 59 
 59 
 56 
 57 
 54 
 65 
 65 
 
 96 
 93 
 86 
 96 
 93 
 81 
 93 
 93 
 93 
 86 
 86 
 86 
 83 
 69 
 80 
 90 
 90 
 90 
 85 
 85 
 78 
 84 
 81 
 90 
 84 
 
 61.5 
 59 
 54 
 58 
 59 
 62 
 67 
 61 
 61 
 57 
 63 
 61 
 59.5 
 60 
 62. 
 64 
 75 
 73 
 66 
 68 
 67 
 66 
 64 
 70 
 72 
 
 60.5 
 54 
 52 
 56 
 58 
 60 
 65 
 57 
 58.5 
 54 
 60 
 59 , 
 55.5 
 53.5 
 58 
 57.5 
 72 
 68 
 62 
 64 
 62 
 61 
 60 
 67 
 67 
 
 61 
 49 
 50 
 
 @ 
 
 58 
 64 
 54 
 56 
 51 
 58 
 57 
 51 
 46 
 55 
 52 
 70 
 65 
 59 
 61 
 58 
 57 
 57 
 65 
 64 
 
 97 
 70 
 86 
 86 
 93 
 87 
 90 
 78 
 84 
 81 
 84 
 87 
 75 
 60 
 78 
 75 
 85 
 76 
 78 
 78 
 73 
 73 
 78 
 84 
 76 
 
 
 July 20 11 p m 
 
 July 21, 7 a. m 
 
 July 21, 11 a.m 
 Jul> 21, 3 p. m 
 
 July 21 7 p. m 
 
 July 22, 7 a. m 
 
 July 22 11 a. m 
 
 July 25, 3 p. m 
 
 July 25 7 p. m 
 
 July 26, 11 a.m 
 
 July 26> 3 p. m 
 
 July 27, 11 a.m 
 
 August 4, 11 a m 
 
 August 6, 11 a.m 
 August 6, 3p.m 
 August 7, 11 a. m 
 
 August 7, 3 p. m 
 
 August 9, 3 p. m 
 
 August 10, 12 m . . 
 
 August 10, 3 p. m 
 
 August 13, 11 a. m. 
 
 August 13, 3 p. m 
 
 Averages . . 
 
 56.1 
 
 53.9 
 
 51. 8, 85. 5 58. 9 
 
 56. 7 54. 9 
 
 85. 8! 63. 6 60 
 
 57.1 
 
 80 
 
 
13 
 
 TABLE B Continued. 
 
 Date and hour. 
 
 Air-meter. 
 
 Revolutions perminute. 
 
 i 
 
 Remarks. 
 
 \ 
 Lineal feet. 
 
 Rate per hour cor- 
 rected for error 
 of instrument. 
 
 July 17 11 a. in 
 
 3, 932, 748 
 4, 212, 799 
 4, 494, 530 
 4, 758, 650 
 5, 275, 230 
 5, 594, 040 
 5, 883, 420 
 6, 196, 250 
 6, 714, 720 
 6, 949, 060 
 7 431 440 
 
 69, 953 
 62,284 
 63,270 
 
 98.6 
 95.3 
 96.5 
 87.2 
 72.1 
 109.7 
 98 
 70.5 
 70 
 82.3 
 74.5 
 70 
 79 
 102 
 94 
 49.9 
 108 
 156.1 
 147 
 143.2 
 97.5 
 131.1 
 97 
 92.3 
 103.3 
 
 40 
 40 
 40 
 40 
 40 
 40 
 40 
 40 
 40 
 40 
 40 
 40 
 40 . 
 40 
 40 
 30 
 40 
 40 
 40 
 40 
 35 
 40 
 40 
 40 
 40 
 
 Ice in drying box. 
 Do. 
 Do. 
 Do. 
 Do. 
 No ice in drying box. 
 Do. 
 Ice in drying box. 
 No ice in drying box. 
 Ice in drying box. 
 Do. 
 Do. 
 No ice in drying box. 
 Do. 
 Do. 
 Do. 
 Do. 
 Do. 
 Do. 
 Do. 
 Do. 
 Do. 
 Do. 
 Do. 
 Do. 
 
 
 
 
 July l' 7 a. m 
 
 49, 852 
 57, 717 
 68,253 
 74,297 
 47, 418 
 55,556 
 
 July 21* 11 a m 
 
 July 21 3 p. m .. . ....... 
 
 July 21 7 p m 
 
 July22'7a.m 
 
 July 22' 11 a. m 
 
 July 25' 3pm 
 
 
 7, 614, 730 
 8, 531, 330 
 8, 837, 830 
 10, 260, 440 
 12, 014, 130 
 '13,870,750 
 14, 324, 130 
 16, 340, 500 
 16, 753, 600 
 17, 545, 820 
 18, 134, 200 
 18, 465, 300 
 21, 168, 970 
 21, 456, 800 
 
 43, 031 
 55,547 
 72,784 
 64,135 
 33, 701 
 74, 340 
 107, 683 
 93, 777 
 98, 112 
 
 July 26 11 a. m 
 
 July 26 3pm . ... 
 
 July 27 11 a. m 
 
 August 4 11 a. 111 .... 
 
 August 6 11 a. m 
 
 
 August 7 Ha. 111 ... . .... ..... .. 
 
 
 August 9,' 3 p. m 
 August 10, 12 m 
 
 August 10 3 p m 
 
 87, 015 
 64, 830 
 68, 360 
 
 August 13, 11 a. 111 . . 
 
 
 
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