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Les cartes, planches, tableaux, etc., peuvent Atre film6s d des taux de r6duction diffdrents. Lorsque le document est trop grand pour etre reproduit en un seul clich6, il est film6 d partir de I'angle sup6rieur gauche, de gauche d droite, et de haut en bas, en prenant le nombre d'images r.6cessaire. Les diagrammes suivants illustrent la m^thode. 32t 1 2 3 4 5 6 ^ {' —OF— THE IMP.ROVBD 'NEWTONIAN ASTRONOMICAl, GI4OBE. A SC No. 1. Terrestrial Sun View and place of the Pole at Vernal Equinox, March 20th. No. 2. Terrestrial Sun V'iew an.l place of the Pole at Northern Solstice, June 2i.si. A MANUAL OK Tllli IMPROVED ASTRONOMICAL GLOBE, As Constructed Strictly in Accordance with the Principles OF Modern Astronomical Science, BY M. TURNBULL, SCHOLAR OF THE BIRCKBECK INSTITUTE, LONDON, ENG. H Northern szio^»rz> Bx»xa:'x^ia-. ILLUSTRATED. "It is difficult to say when Astronomy ««,/,t and Geo.'raphy henins, the t joined together. —Prof. Simon Nf.vvcomh, Washington, D.C. wo sciences are so J Entered according to Act of Parliament of Canada in the year One Thouwnd Ki='"-' «"'" «>->"'» e nt e .s exactly s.tuatc n, the celestial plane of the globe's equator, an W. o tn,c h,eh .s universally named the VK„.v.. .,t„N„x, a term wh eh impH al ,ngl,ts ,„ every pl.„„ between the two poles of the globe. The import ne ft^ A ,1 n """ . " "°'°™"" '""^ '" ""■•' ■" " S™"l^(,'.- to constitute he Alpha and On.ega of the two sciences, because it is the chief source .whence is denved not only the true place in the ecliptic, where the poles of the globe is Pn^^rin g.ves the duratmn of the three great annual periods of tiu.c knoJn in astronom e geography, a., the .,.,o,„„fa.„, J,e *:,,,o,«(, and the m..- Y,ur. With the aiov exp a„at,on ,t will now he easily understood (especially when it is borne in nnndtl.atitisan unchangmg geometrical law in the doctrine of the sphere, that the .solsticial plane where the es^oftr T ' """'' '■" "" "'""■" "-'^■"'"■-. ■» "'->- a ri,u..„U. or 90' east of the above OKKAT .,t.,.ox,.,. u.,T of ti„,e, that the n,otlo„ and true place of the gohesax.s must constantly v,„„™ westward, in close unison with the annua p..»ss,on of the equator of the globe round the Zodical pole. It n.ay he oKserved Z w the sun W.S on the equator and at the same time in AHe, it w,. i the time, of I Ihstrmus „,pparehus, who fl„t el.,si«ed the stars, now over two thousand years Catalogn,!, Alpha Aru. ,„ the head of the r„,„ has a right asce„.sion of ,h. .,«„, 4* or ,s nearly thirty deeree, east of the sun at the vernal equinox in the pre- sent age ; hence when the phenona-non now takes place (March 20th,) the sun is passing 12 THE TEKRESTIUAL OLOHE the stars in *;he constellation Pi^chtm or Pisces and the northern solstice in Gemini (June 2lst) as arranged on the new ecliptic plane; however to point out practically here to a student who may possess an astronomical glol)e we will give a direct illustration with the apparatus. Bring the sun's place on the ecliptic plane to the vernal equinox, March 20th. It will then be observed that the great luminary has just passed in right ascension a star of the fifth magni- tude in the constellation Pisces, and marked 33 frou. Flamstead's numbers, or according to the Greenwich Twelve Years Catalogue, it has aright ascension 23h, 57m, 39s, which iso'nly two and a half minutes of arc behind the sun when it is crossing the equator, hence this object is among the nearest, optically to the sun at present, when the above great annual phenomenon takes place. From the foregoing facts in modern astronomical geography it will now be almost unnecessary to point out to the .scientific geographer that it is a"" .scientific fraud committed, the placing of terrestrial globes in libraries and schools which have their axis placed in Cancer and Capricon,the constellations where all the old globes have it placed and the error extends also to the title or name of the tropics of declination as they are always situate in the solstices of the passing hour. The scientific pupil has to bear in mind the fact that, the terrestrial poles revolve around the axis of ecliptic in somewhat over 26,900 years, —the orbits of the two poles being constantly under the Celestial Arctic And Ant artie circles. It will be remembered that the last important civil time, corrections which were intro- duced by Pope Gregory, known universally as the "New Gregorian style," is entirely founded upon the unchanging zodiacal arc of 90', which always exists between the vernal equinoxal plane and the northern solstice. The calendar of days and the northern solstice by this means can never alter, thus securing the regular flow of Spring, Summer, Autunni and Winter ; among the whole list of new problems which the astrononn'cal design of mounting has created andean solve, few are more instructive and elevating than the annual history it gives of the sunshineat the two poles around the ecliptic axis It will be remembered that it was stated that the ecliptic plane consists of two concentric circles, the inner portion being made to revolve around the globe ; this circle carries three most useful appendages for solving some vtry important new problems : the first consists of an arrangement to represent the sun's centre which moves over the days of the calendar and at the same time the degrees on the fixed ecliptic. In general this part is the first to be used in solving many of topographical (,ues- tions ; the second is a brass .semi-circle graduated into 90' each which revolves around the sun's centre and moves with it to indicate how far the observer is from a zenith sun: this part al,,o t ..blesone to determine the solar energy on the different portions of the crlobe through the 1. .' that heat diminishes as the square of the angular distance increases from a zenith sun. I„ addition to the functions of the above circh' the inner circle has the property ns rsEs IN- (;e()grapht. 13 to keep the da.ly solar terrestrial meridian upon the sun's apparent centre, thus affor.lin. the means o .leternnning the apparent noon for any place on the earth. In connection with this part ot the apparatus it will be observed by those who possess this globe, how truly the suns n er- lian'" h' '^^7Z "" ''"'''''' '"''"^'^ "' '^"*"'^" "''' ''^'^'^ ^' ^^e movable brass cally whence they ar.se, as the sun n.oves east in its daily right ascensions. The next representative circle to be described is that great Beit of Lif move twice over the chord of the segment of forty-seven degrees, or twice the angle of its axis witii tiie ecliptic axis. Hence the conines of those two quadrants will point out the true place of the pole and indicate the direct angle of the axis with the ecliptic axis on any • lay in the year. The great advantages obtained by the introduction of this addition to the astronomical globe, are,,/i7's^ that it brings directly before the eye the real perspective motion of the poles of the earth in the solar system, which the design shows to be a straight line during both their seasons of sunlight and darkness.* Second, that the twilight circle also furnishes an expert geographer with everything necessary to chart on a planosphere of the earth any parallel of latitude at any period of the year. The next and final part to be described are the mechanical arrangements for finding either the siderial or the true civil time. It may be mentioned, that us lioth the world of commerce and of science have accepted the meridian of Greenwich for the unification of terrestrial longitude, the study of geographical astronomy is just what is needed to convey thoroughly, both optically and mentally, the new time systeui adopted. The solution of time problems by the use of the modern arrange- ments is a process in miniature somewhat similar to that which may be observed at fixed times daily in any national observatory. In the new globe the position of the great solar luminary is represented in its true place, in right ascension among the ecliptic stars, and the constant changing angles of the NOON brass meridian with the ecliptic axis are all well illustrated. It will be observed, from the two cutsof the design, that there is connected with the globe's axis a large liovr circle upon an improved plan; it revolves roinul the southern axis of the globe, and is attached to the daily eastern progress of the prime meridian of any place. The circle is graduated into degrees of arc, and likewise into hours of civil time : thus, with the use of a moveable vernier placed around the globe's southern axis the geographer can solve the solar right ascensions for any hour, even to one-fourth of the sixtieth of an hour, of civil time. Before closing this descriptive account we wish to call attention again to one of the most prominent of the new problems which the astronomical system of mounting is especially adapted to illustrate and solve. * It is generally well understood to be one of the highest and most useful lessons in geo- graphy, to be able to construct a coi-rect planosphere of the globe for any day in the year, one showing the real path any city will take, or the direction any parallel of latitude will have irom sunrise to sunset. In acquiring this useful accomplishment it is claimed that the new globe has no competitor in furnishing all the elements oi which the solution of the problem rests. It may first be observed that the two poles of the globe, as formerly shown, viewed from the *As the angle of the globe's .ixis 23' 2,S", is aJway? a constant quantity with the ecliptic plane, making the ulterior ANOl.Es eqiial on every day of the year. Hence the pole must appear to describe annually the aljovc straiuht line, Vuc 1st and 271I1. ft ' - • ITS rsKS IN (lEOOHAPHY. 15 n evolve w.th the season, through a STHAroHT une. This line is Just ...ual to the dlan.eter the senn-cn-cular scale ot ,nnes and eo.lnes placed upon the .ovoi ving twilight circl. Hence he annual perspect.ve n.otion of the poles round the ecliptic axis becon.es the chief farf'r oepend upon incompleting the „.ap: the following .nay be used to n.ake the foregoing Ma.ch. At tins penod, wlueh ,s the great aMronomieal zero siderlal ti^^e period, the north pole wd be seen to be,ust leaving its last six ninths' obscuration and entering upon thedir dlununate d.sc of the earth s snnli.ht perspective. (See cut No. 1.) Its pLe'is now^ below the twd.g t cu-cle.and upon the very ./,. of thesunlight perspective of theglobe. A.^n inove the sun .s place in right ascension, .say 2h. or 80^ Now it will be observed that the s^n in the ca endar of days ,s over the 19th of April. At this time the place of the north pole is indicated by the scale where it has moved towards the ecliptic axis to IW on the line of counes so this is the distance of the pole fron. .oliptic axis for the given period. Hence a straight hne from the point through the globe's centre will g:ve on a chart the true angle wh.ch the globes p..;,..i.e ,,,, ,,, ,„ ,,, j,,, ^^ ^^^^ Again,move the sun'splace 6h O.-90 m nght ascens.on, which occurs on the 21st of June. At this period it will be apparent that th . globe s ax,s hes exactly tou..'ds the cen ire of the sun', di.c, and that both are situate in he sohst.c,a plane. (See cut No. 2.) Hence, since March 20, when the pole was first seen in thesunhght horizon, till June 21st, it has moved over the entire length of the cosine of 90° as indicated by the twilight scale. Moreover, it will be further observed that durin.. the next three months of the poles perspective motion, it will finish its six months track iirsunlight which astronomically takes place on the day of the autumnal equinox, (Sept.22nd.) The cosines and sines on the perspective twilight scale are placed for every ten degrees of the solar ri.ht ascensions, thus ensuring a numerous train of places to point to where the pole is situate during Its annnal motion. It will now be apparent, from the foregoing paxoramic motion of the POLE during the four sea.sons, how useful the astronomical globe is in solvin. prob ems, or in charting the perspective surface of the earth. In the study of this division of the science, and to give a fuller exposition of the principles contained in several of the above pamgraphs, we herewith insert in the next section, two finished CHA^^^^ of the two paths which Toronto describes in sunlight on March the 20th and June the 21st, with a lull ex- flTrr'Tn'""' ""''"' "''^'"^^ ''''''' P^^^*'^^^ ''y *'- *hree distingu- ished astronomers of Greenwich, vix : Messrs. Flamsteed, Halley, and Bradley ITS USES IN aEOGlUPlIY. ir SECTION II, Before proceeding to project geometrically a chart of the globe or any hemisDherical paralle of atitude through sunlight, it .ay be servicable to soL readers to prZe' aTw things for describing the terms used in the delineation. A.-It is now CERTAINLY known in modern OEODAESEA.that the earth is nearly of a globu- lar shape. However, when it is viewed from a great distance, such as the sun's cLtre fw^ Z::::'" '-'-^'-^^'--^ ^^^« ^^^ — - nigh, now tMsappearance iTel':;: B By the constant rotation of the globe around its axis, every place on the surface describes a circle equally distant from the equator, and the plane described by the p named the path of the vertex of that place. C._The phases of the paths of places in sunshine on the globe s disc, are not always of he same form; they all differ with the sun's high ascension ; when the sun is in eithe o he equinoxial points, the paths of all places are represented by straight lines such as they are m cut No. 1. and when the sun is in any other degree of the zodiac, they are represented by ELLIPSES moreorless eccentric as the sun is nearer to or further from the equinoxLl no . .^-^" ^^"^"'!^^"f f "^^^ P-^hs on the earth's disc special attention must be had to the PC ition of the axis of the globe in the direct beam of sunlight, as every parallel of latit changes its position with the ecliptic axis at the time. R-When the sun is in the ascending signs, which is a period from December .1st to itTin H T ' t '' "'' "" *" "" "^'' '"^^ "' *^'^^ ^^^^P"'' -•« ^-« ->* ^- 1). but" when at IS m the descending sig '. axis lies to tb^ left hand. When the ,sun is in e her of the 18 TIIK IKIlltESTKIAI, (i|,(»HK solsfcieial points or plan, tht; axis coiucides (seo cut No. 2), and when it is in the o(|uinoxial they make the great.'st un^rK., viz., 2.'} 28', Wiicn the sun is in any of the six northern signs, viz,, Pisces, Aries, Taurus, Gemini, ( ancer, and Leo. the north pole of the earth is in the enlightened part of the eartli's (ii,se, anil when he is in the southern signs, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aijuarius, the north pole of the earth is in the obscure or sunless part of the disc. F.— The transverse or largest diameter of any oliptical parallel of latitude is always at right angles with the globe's axis, and the conjugate or minor axis of any elipse is constantly -regulated in its length by the solar longitude or right ascensions of the sun, and which con- tinually afiects its declinations, thereby altering daily the dimensions of the minor axis which any place has from eiiuinox to solstice, A GEOMETRICAL PROJECTION ON TIIK OLOBE's NORTHERN HEMISPHERE OF THE PATH OF TORONTO ON MARCH 20 AND JUNE 21. (SEE DIAGRAM ON OPPOSITE PAGE.) ^(|uinoxial northern irth is in •ffo, Libra, bscuro or ilwaya at ionstantly ,^hich con- iinor axis PATH OF i I . IsiM^sal cosiNks Ion twilig ht cihclIe TO ILLUSTRATE CUT N° I TO ILLUSTRATE CUT N9 2 w i'HE TEHRKHTItlAI (;L0BE Wifiiau^ 'onvenicnt mdiu lus A D, lifserilH) the .semi-circle A B C, upon the centre D, draw th«- »tmij/ht iiii.- D H, perpeiuiir ular to Hu) diaiiiuter A DC, so A D (J shall represent a part of ihc L'cli| ti/* plane and D B its axis. , 'ke the chord of the t)hli(iuity of the jflobe's axis to ecliptic plaii^; correspondinj,' to radius A D. and .sot it off" on the circle ABC upon each siile of B to N and M, draw the line N M cutting ecliptic axis in O. Now, oa formerly shown, the pole of the globe, as viewed from the sun, revolves twice in the course of the seasons through the lino N O M, and since N is its place at the vernal equinox (see chart No. 1), its distance on any day from N will he equal to the cosine of the scale on the face of twilight circle. On the 2 1st June, the present case, th<; .sun's right a.scension, is exactly six hours or 90". Hence as the cosine of 90 is always e.|ual to radius N, () will he the extent which the terrestrial pole has shifted in the solar perspective since the 20th of March. Therefore, O on the ecliptic axis is the true or the real place of the globe's pole on Juno 2l8t, or, in other wordj, the angle of the earth's axis with the ecliptic axis completely vanishes at the two solstices. Next,' to draw the path of Toronto on the northern half of the globe's planosphere, it may bo mentioned, that had the latitude of the o.ity been the same as the sun's declination, Toronto would bo seen at D, the centre of the p.ispective disc. However, as the city's lati- tude, in round numbers, is 44°, which exceeds the sun's declination by 20" 30', take the sine of 20° 30' to the radius D C, and set it off from D to 12, which point on the axis will be the true place of Toronto at noon on June 21st. Again, it can be easily understood that could Toronto be seen from the sun at midnight on June 21st, its place would be somewhere upon the line D B, and north of the point 12. Now the point antipodal where the sun is vertical at midnight, as seen at D, is as many degrees SOUTH of the equator as the sun's declination is north, plus 20" 30'. The distance of Toronto, then, at the above day in the year will be equal to its latitn '; added to the sun's declination, which amounts to 67" 30'. Therefu- , with the sine of GT ,;;(* ^-i off froir Tj upon the line D B to 12, which is a little beyond 0, the point repres . f n^ th^ true perspec- tive place of Toronto at midnight. It will now be observed that the line 12 H 12 will be the conjugate or minor axis of the ellipse into which the parallel of latitude appears projected from being £?er .bliquely; and the point H midway between 12 and 12 is its centre. Hence, the line 6 and G at ^ :■, ^V cough H perpendicular to the globe's axis D B, (cut No. 2,) or D N, (cut No. 1,) is thp u' trse >. longest diameter. To find the length of the longest axis of the above elliptic. ,^,r! u~e the cosir • -f the complement of the latitude of Toronto, viz., 44°, and setting it orfbo»;,i ways from H to 6 and G, those points on the Disc will be the place where the city will be seen at six in the morning, and at six in the evening of June -■* f fTS USES IN OE(KiKAPHY, 21 2l8t. Lastly, to trace the place of Toronto at my hour of the twenty-four, the following geometrical (let/iils have to be ciMSoly attended to. With a radius e.,ual to H « on the trans- verse axis of ellipst, take the sim, of 15 a.i.l set it off on each side of the point H on the line (J and 0; .lo the same with the sines of MO'. 45 , iiO'. and 75, as shown on the ch Tt No. 2. Then through these points draw lines parallel to D B, the globe's axis. Next oi. the .iua^ and set it off on each si.i.. of the tm*^- verso of ellipse at the hours 1 , II . on the right hand of H. In the same way sot oil the sin. s of 30°. 45", m\ 75' on each side of H in the transverse lines of ellipse and the point .tain- ed in this way represent the place of Toronto at the .lifferent hours of tl twei four Thus an ellipse .Irawn as shown throudi all the various places will represeuc theam-an^it path of the city for the above selected ,Jay. Itw^ll be seen from chart No 2 tl ,t the parallel of Toronto touches the perspective peripher of the disc at a few minut. fore 4 a.m.. andata few minutes after 8 p.m.. and thes. places divide the path into , parts, one representing the path by day and the other by night. To construct a chart of a parallel of latitude at t.,e equinoxes, very little wor- 19 required to make the delineation (see cut No. 1.) At this annual period, as the sun centre is in the equatorial plane the direct rays as formerly xplained fall upo, the edge o< every plane of latitude from the equator to the poles, and l-ing all at right angles to th- globe's axis the path of every place appears as a straight line on the globe from sunrise to sunset. The line, therefore, from G and 6, in chart No. 1. is th. place and appearance in sun- light of the path of Toronto at the vernal equinox, March 20. a ,d the ttgures show the place of the city during the day. The hours above the line, or path > and 6, being the midnight time and those below represent the different hours in sunlight. ITS USES IN GEOGBAPHY. 23 ? SECTION III. PRELIMINARY OBSERVATIONS ON THE " DOCTRINE OF THE SPHERE" AND THE USE OF AS- TRONOMICAL CIRCLES TO PHYSICAL GEOGRAPHY. Before, dealing with the solution of problems the Newtonian Globe is adapted to solve It may be useful to some to call their attention to a few of the points in the " Doctrine of the Sphere" which relates to those circles placed round the Globe with its new arrange- ments, and supposed to be extended to the heavens. In the first place it is important to bear in mind that wherever a spectator is situate in the mundane sphere his eye will be the centre of the sphere as applied to the open sky. The fixed stars will always have the same magnitude and the constellations the same form, whether he view them from the earth or in the mind's eye from the sun. Hence generally it is instructive to view that immense scene from the mathematical standpoint, which has only position without any magnitude Moreover, in order to form just ideas of the earth's surface with all its diferent parts ■ of their situations, magnitude and distances from each other, and from our place upon' the globe. Many circles are supposed to be described and being produced to the heavens divide the concave into similar parts, whereby we can speak more intelligently of their vast extent and describe the phenomena better than could be done without such contrivances. Now in physical geography all these circles are called " Circles of the Sphere," and they are either great or small. Every great circle hath the same centre with the sphere and a small circle divides the sphere into two unequal parts. The axis of a circle is a straight line'passino- through its centre, and consequently is perpendicular to its plane. The polos of a great circle are two points in the surface of the sphere diametrically opposite and equally distant from every point of the great circle. A small circle, like the various latitudes on the earth which are all parallel to the equatorial plane, have the same poles. Great circles which pass through the poles of another great circle cut it at right angles and are called secondiaries Some cu-cles of the sphere retain always the same position, and are therefore named fixed circles. On such circles the properties of the astronomical o-lobo chi.fly depend ■ others depend on the position of the spectator and move along witl hi„, and are called movable cu-cles. A great circle, when it is described on the earth, is called the e<,uator and 24 THE TERRESTUIAL GLOBE when extended to the heavens is termed the equinoctial. With its secondaries and all the parallels of latitude on the globe are fixed circles ; these are delineated on artificial globes and on all maps of the surface of the earth. The axis of the equator, called the axis of the world, is in the same straight line with that of the earth, and its extremities are the north and the south poles, whether of the earth or of the heavens. Great circles passing through the poles and at right angles to the equator are its secondaries, and with respect to places on the earth they are named meridians. In the heavens they are called circle of right ascension and sometimes hour circles. Latitude is the distance of a place north or south from the equator, and is always reckoned upon the meridian. Hence places which lie north and south of each other have the same meridian and have noonday at the same instant of time. Longitude is the distance of a place from the prime or first meridian, reckoned upon the equator, and according to the new method of calculating longitude it continually runs et-st- ward round the globe until the reckoning ends where it began. Topographical longitude of any place is therefore an arc of the equator between the first meridian and the meridian of that place, and may be expressed in time by counting 15° of the equator one hour, every de- gree four minutes, and every minute four seconds. The length of a degree of longitude on the equator is sixty geographical miles, but a degree on the parallel of 60 degrees is only 30 miles. The way to measure the diflferent arcs by the new globe is given in the section con- taining the list of problems. Parallels of latitude on the earth, being extended to the heavens, are called parallels of declination, and four of them are especially remarkable, as they form important factors in the use of the Astronomical Globe. They are distinguished by particular names, viz.: The two Tropics and the two Polar Circles. The two Tropics are produced by the inclination of the globe's axis, to the ecliptic axis, having each an angle of 23' 28\ We have scientifically demonstrated from Loomis's American Catalogue of the Stars that the sun's place on June 21 is in Gemini. Hence, in the present age, the name of that constellation is now the real name of the tropic in the northern hemisphere of the globe. In the southern hemisphere, at the solstice, as the sun reaches Sagittarius on Dec. 21st, the name of thai constellation for the same reason becomes the correct name of the southern tropic. These two parallels are the limits of the sun's declination annually, which regulate greatly the temperature of the two hemispheres. The two polar circles are de- scribed round the poles at the distance of the axial inclination. That in the north is called the Arctic Circle, which names its centre the Arctic Pole. The other, at the same distance from the South Pole, is called the Antarctic Circle, as being opposite to the former, and for the some reason this pole is named the Antarctic Pole. On the surface of the globe, be- tween the two Polar Circles, the sun rises and sets daily, dividing the twenty-four hours into day and night. But within tlie Polar Circles there are .six months in which the sun md all the cial globes axis of the the north ig through places on t ascension from the north and it of time. i upon the runs enst- •ngitude of ei'idian of , every de- ngitude on is only 30 iction con- ded to the irkable, as tinguished topics are 1 angle of ue of the le name of lere of the s on Dec. ne of the Uy, which es are de- b is called e distance r, and for ;r\ohe, be- our hours h the sun 25 ■ »s, or shadowless. It will be noticed that n, the above .on the ye^is no^ divided mto summer and winter as it is in the other .ones of both hen.ispheres Th T perate .ones of both hemispheres are next to the Torrid, one on the north and the other on the south side of ,t The spaee on the globe between the Tropic of Ocmini and IheA , Circle is called the North Temperate Zone. It is « degrees lide .Z::^'2^Z of Eu„pe, the grea er part of A.,ia, a small part of the north of Africa, and a consider!." part of Nort Am...ca. I„ *is .one, the sun being always south of the .nith, the sh low of the mhab.tants fall northward at noon. The days and night, are „nc,,„al e.cept at Z Cr^ile, rs called the South Temperate Zone, which is also 43 degrees bro.ul -.n.l ine]„ small pa^ Of Africa and a great part of South America, meludi; New h".::!,: ,! her of the adjacent island. Hero the days and nights are always uiie,,„al, except at the e„u,n„xes. The s„„ being always north of the .enith the noonday sh.^o'ws f t e'i ih 1 .ats fall contnnually southwanls. Hence the inhabitants of the two Temperate Zones « styled Heteroscians, because their noonday shadows always fall the same way The space within the Arctic Circle, having the North Pole in the middle of it, is ca'led the No t" Irftl^C T °".,T""' "'■ *"" '"'""* ~'"' '^""" "'■""'■'■^ "-- T'- '"-"'e^ le Arctic Cli-cle is *7 degrees, or .,,820 geographical miles, and embr,«es a part of Europe airf Asia, Ea-st and West Greeulaud, with Nova Zembla and some of the nortWru parts of N "h America There is very little habitable land here, and few inhabitnits. Th South Fi ' Zone IS a space ,n extent and 1,1 all other respects the sai is the Northern Frigid Z only e.ss land ha, been ,li.,c„vered in high southern latitudes. The inhabita ts ' ^ ^ .rigid .ones are named P..uscua».,. because when the sun is visible their shadows fall ZlZ 20 THE TERRESTRIAL (JLOUE every point of tlie compass in every axial rotation of the glove. In the use of the Astrono- mical Globe it is of great importance to remember that the newly arranged ecliptic plane divides l)oth the earth and the heavens into northern and southern hemispheres, and the signs upon it are tlivided in the same way. The first six are called the northern signs, be- cause they are all on the north side of the equinoxial ; and the other six are called southern signs, as they are southward of the equinoxial plane. The Ascending signs begin at the south point of the Ecliptic Circle, viz., when the sun reaches the southern tropic ; .they are Sagittarius, Capricornus, Aciuarius, Pices, Aries, and Tarius. The other six are the descend- ing signs, viz., Gemini, Cancer, Leo, Virgo, Libra, and Scorpio. The meridian, which passes through the equinoctial points is called the equinoctial colure, and that which passes through the solsticial points is called the solsticial colure. These two great meridians cut each other at right angles in the poles of the equinoctial plane, and divide the ecliptic and equinoctial, as also the whole visible heavens into four equal parts. It may be noticed in passing that the equinoctial colure is called the First Celestial Meridian. The right ascensions or hour circles of the equator and the longitude upon the ecliptic plane are al. ckpned from the above great celestial meridian. It will now be observed by the student that the poles of the ecliptic are points situate in the solsticial colure 23° 28' distant from the poles of the earth. Hence in the use of the Astronomical Globe this part in the study of the subject should be clearly understood, as it optically illustrates that while the earth turns upon its axis, and at the same time advances east in its orbit round the sun, conjointly with the axial parallelism of the globe, it makes the pole of the ecliptic plane appear to describe annually the two polar circles. Hence in the use of the new globe, the above facts are worthy of the closest attention, as it is from tlie aforesaid conditions that the motion of the terrestrial pole in the sunlight has its source and shows how the Newtonian globe so well illustrates this dyruimical phenomenon. Great cn-cles passmg tiirougli the ecliptic poles are called circles of longitude ; longitude is, therefore, an arc of the zodiac between the vernal eciuinox and the required longitude, in the order of the signs. Small circles parallel to the zodiac are named parallels of latitude in the heavens. The ecliptic constellations occupy a celestial belt embraced between two parallels of latitude on each side of the ecliptic plane, where all the orbits of the planets, except one or two, are to be found. In former ages these constellations were situated as they are at present in the heavens, but now in a different situation as regards the terrestrial globe, with its various annual perturbed motions, and principally influenced by the slow mo- tion, 50" of an arc annually of the equinoctial points westwards, called the precision of the equinoxes. In consequence of tliis the stars in the zodiac appear fui'tliereast tlian formerly, so that PicEs is now in the place where the sine Aries was 2,000 years ago, as- before no- ITS (JSES IN fiEO(JHAPHV. 27 ticed, and the constellation Aries is in the sine Tauus, &c., &c. For the sake of tracinc. the echptic constellation with greater ease astronomers suppose them to be n.arked by the^ut- hnes of some animal or figure. By this means the motions of the dift'erent men.bers of the solar system are more readily compared and described ; although with many of them it is almost impossible to trace the slightest resemblance. Objects ifi the sphere which have the s.nie nght ascension with the sun are in the meridian at noonday; but those which have the nght ascension otherwise come to the n.eridian either before or after the sun, and here the hours are reckoned from one to twenty-four, because the day now begins and ends at noon Ihe nght ascension of the sun increases about one degree or four minutes of tin.e every ,lay but the right ascension of a star is the same for a long period ; the variation seldom exceeds' hve or six seconds of time in a year. ITS USES IN GEOGKAPHY. 29 n SECTION IV. PROBLEMS IN PHYSICAL OEOGUAPHV, VVHOUOHT OUT BV THE NEWTONIAN ASTBONOMICAL GLOBE. Problem I. Solve with the Olobe. IIWb optically the fo,,,- se„,„„» of th„ ycav, by tl,o perspective motion and place eiptrpTane '" "' '""""' °"""°' "''"°' '"""^ ''"' "^'"' P'™"'"""' '-"'' "'« RDLB)._Bring the Sun's place to the Vernal Equinox, the 20th March. At this periot ascension be .Sh, or 120°, which of the sines on the scale pomts down to the globe where the pole is situate in the sunlight, at the tune, and what is tJie direction m which the globen axis lies in the su-is rays ? Answer.-The sine of 120^ and 240' of the left hand ,,uadrant points t<, the place of the pole and the axis in this case lies in sunlight to the left hand of the ecliptic axis. Prohlem VIII. At any a.ssunied place within tho tropics H„d all the places which have the .same distance from it within the circle of solar illumination. RULE.-Bring the sun's place in the ecliptic directly over the given place and the places required will all be shown in degree, by the brass graduated semi-circle which revolve round the sun's centre. Q. What places have the same distance from La Plata, in South America ? Answer.-Congo (Guinea,) Fernando Po., Timbuctoo, Morocco, Cadi^, and Orgeon City. PnOHLEM IX. Dr. Kane, in 1854, spent that year at Renssel.aer Bay in the arctic circle, in latitude 78" 30', how long was his arctic day, how long was the sun absent, and how often did it rise and set to the place ?* Solve tvith Globe. RULE.-Bring the place to the apparent solar meridian and exactly below the front edge of the great terminator or twilight circle, then screw firm to the globe's axis the hour vernier, and move the sun's place till Renssela^- Bay is again on the meridian and in front below the twilight circle, then the problem can be solved. Answer.-The sun shown constantly from Feb. loth to Oct. 25, length of the day 252 rotati(ms, and the sun was absent 113 days ; also the sun rose and set from Feb. 15 to April 16, viz., 62 days. *Thc following abstract has been taken fro.n Dr. Kane's^n'otes, ,o enable the reader to con^p^r^i^^^T^^^r^i;^, solution wuh what he actually experienced at the place during the year-the reader being expected, with the globe before him, to place the sun in the ecliptic to the days mentioned in the Doctor's notes :— RENSSE.A.K liAV, OcU/,er /^/'.-The long staring day, which has clung to us for months past, to the exclusion of the stars, has begun to in erm.t Us brightness : even Aldebaran, the red eye of the " bull, ' flared out into familiar recol lection as early as ten o cluck, and the heavens, still somewhat reddened by the gaudy tints of midnight ' JT Capella and Arcturus, and even that lesser light of home memories, the Pole .Star. > ta^e us Novcm/.,r 7//'.-TI,c d.arkness is coming on with insidious stcidiness, and its ad-ances ran only be nerceived bv comparing one day with Its fellow of some lim. back. We still re.ad ,hc thermometer at noond.iy wi,iHn,t\uid., and the black masses of the hills are plain for about five hours, with their glaring patches of snow, but all the re«t is darkness bho place of n the scale nd what is ho phice of axis, ! the same 1 the places cli revolve ■geon City. ititude 78°, it rise and the front the hour i in front ! day 252 5 to April 3ve globular globe before exclusion of miliar recol- ;hti gave us erceived by f> ligiu, and is darkness ITS irsES IN OEOOKAPHY. .').') Pk(»iu,em X. To find the longitude of any given place on the globe i _ RULE.-Bring the prin.e meri. Rule.— Briiij,' tlit* movable iiicridiaii over Orconwicii and tlu' place on tlie jfloh.' holow the niLTiilian and over the equator or zero of latitude will he tlie placv re(|uire(l. A.— The place will he on the South Atlantic Ocean, about (iOO miles south of aold Cape in Anhfintie, in Africa. Problem XIV. To find the places which have the same longitude as any given place ? Solve with Globe. RULF.— Bring the given place to the edge of the movable solar meridian and all places from pole to pole, under the meridian have the same longitude. Q.— What places are nearly under the meridian of St. Petersburg ? A. — Odessa, Cairo, and Constantinople. Problem XV. When does the sun rise and set at Edinburgh on June 21st, and how long is the day ? Rule.— Bring the Sun's place to the apparent meridian, and .screw the axial vernier to that plane, then move by the handle of globe the city west till it comes to the twilight circle anil note the time, do the same for the evening hours and the problem will be solved. A. — The sun rises at 10 minutes to S a.m. and sets at 16 minutes to !)h, p.m. Problem XVI. To find all the places over which the sun will pa.ss vertically on any given day ? Rule.— Bring the sun in the ecliptic to the given day, then rotate the globe by the handle, and all the places over which the sun's centre will pass will have the sun vertical on the given day. , Q. — What places will the sun pass over on the following days ? Jan. 5th. A.— Trini- dad, Hebrides, Mauritius Isle, and Madagascar. On April .-)th. Colombo, (in Candy) Caroline Islands, and Borneo. Problem XVII. To find how many geographical miles make a degree of longitude at any given parallel of latitude ? Rule.— With any suitable appliance, take the distance between two places on the "iven parallel of latitude, and note the number of degrees is enclosed on the equator, multiply the number by 60, divide this by 16, and the result will give the geographical miles. . i IT USES I.V iJKiwJHAI'HV, 85 low '(t/>e ,: Pnn|U,KM XVfll, To fiii.l at any place th'u sun's altitude (.r .listaiicn in .K';,MVes from thu solar tenniiiator. or whero it rose in tin- iiiorninjr on any day and at any hour ( Rui,E.— Brin^ tho sun's centre to the meridian for tiie day and fix the hour's pointer to the ttbovo place, rotate the ^rlohe by handle till the place is just below the face of twiliKht circle a.ul note the hour; then briny the p..inter to the re.piired time, and the number of degrees it pnasea over the hour circle will be the altitude; sought. Q. What is tile suns altitude at Chicago, on June lOth at H a. m. A. The sun's altitude is 55" PUOBLEM XIX. On tho Island of Disco, .stands the capital of CIreenland, withi.i the Arctic circle. When does the sun cease to rise every year, and on what day does it again appear at the place ? RULE.-Briug the south of Di.sco to the front edge of twilight circle, and the place of the sun will point out tho day in the calender when it ceases to rise, move next the sun in longitude east till tho Island is again below th.; twilight circle, and the day when the sun will appear will be found. A.— The sun sets at Disco on Oct. 29th, and rises again the next year about Feb. 8th. Problem XX. Two regions of the globe are each one day in the year astrononncally without either midnight or twilight. Where are they situate on the earth and on what days do the phenomena take place ? Rule.— Bring the sun on ecliptic plane to either of the two solstices and note tho place of the twilight circle on the earth. The distance between its place and the poles give half of the diameter of each of the regions referred to. A.— The two regions are tho Frigid zones, and the two days are June 21 and Dec. 21 n each year. Problem XXI. To find when twilight begins and ends at any particular 'place on an given day ? Rule.— Bring the sun's place in the calendar over tho given day and tho particular place to the solar meridian. Fix the hour pointer on the axis at noon, then bring tho place given to the two edges of twilight zone rnd the pointer will indicate when twilight began and ended in the morning, do the same for the evening portion of the zone, and the hour index will show when the evening twilight began and ended. Q. — When did twilight begin and end at Toronto June 28 ? A. — At 16m. after 2h. a.m., and ended at 24 after 4h. a.m. 36 THE TEKKESTUIAl, OKoiiE Phohlem XXII. As tlie sun passes vertical twice over Navioatohs' Isles, In what degree of the ecliptic and days of the calendar do the circumstances occur ? Solve with the Globe. RULE.-Bring the sun's centre on the ecliptic circle to the degree wliere he first passes over the Isles. Note the degree and the day to the same when next the sun is in the same position over the Isles, and the degrees and the days will be found. A.-When the sun is hrst vertical he is in the 4" Libra on October 25. At the next transit the sun is in 27" Capri- corn on the 14th February. Froblem XXIII. When does the sun rise and set at the Bermudas, on January 27, and how long is the place in passing through the evening and morning twilight ? RULE.-Bring the place to the movable meridian L the day given and screw fast the hour pointer to the globe's axis, while it remains at rest. Then turn the globe west till the Bei-mudas are below the circle marked " twilight begins," and also when tliey reach the point of sunrise. The difference of the two times gives the period of the morning pas- sage through twilight and the latter number the time of sunrise. Do'the same at the evening setting sun and the problem will be solved. A.-The place is in the morning twilight Ih. 25m., and the time of sunrise 4m after 7h a.m. Time in the evening twilight, Ih. 38m., and the sun sets at oh. 2m. p.m. Problem XXIV. To find the longitude between two different places on the globe ? Solve with Globe. RuLE.-Bringoneof the places to the solar meridian and place the axial pointer to that plane, rotate the Globe by the handle till the other place is below the meridian and the degrees of arc passed over will give the difference of longitude. Q.- -What is the difference of longitude between London (Eng.), and Toronto ? A — 5h 17m. west. Between New York and Toronto 20m. in west longitude. Problem XXV. To find when continuous twilight takes place after sunset. How long it continues at the following different places in England, Scotland and Ireland. Solve with the Globe. Rule.— Work as directed in Problem XXL London— Twilight begins May 21st ; ends July 22nd. Bristol— Twilight begins May 21st ; ends July 19, The Lands End— Twilight begins June 4th ; ends July 10. , ITS USES IN (JEOraUPHV. 37 he ecliptic irst passes the same the sun is 27" Capri- ng is the V fast the St till the i-each the ning pas- le at the after 7h. oi liter to neridian A.— 5h. Annea at Edinburgh— Twilight begins May I Gth ; ends August 4. Dublin— Twilight begins May 16th; ends July 26. Liverpool— Twilight begins May 14th ; ends July 27. Problem XXVI. What places in British America have continuous twilight during the various summer months. Solve with Globe. Rule.— This problem, like the last, is solved by the rule in XXII. Every place within the parallels of latitude of 50° and 66° 30' f.ave continuous twilight after sunset, from the end of May to nearly the 10th July, which includes a region in the Dominion from the Lake of the Woods in the south to the southern shores of the Great Bear Lake, besides the Copper Indian territory in the north. So that the twilights are con- tinuous over every fishing lake north of the parallel of tlie mouth of the St. Lawrence dur- ing the above period. Problem XXVIL To find by the Globe the three cases, viz., the Antoeci, Peritoci, and Antipodes of any given place on the earth ? Rule.— Bring the place to the solar meridian and note its latitude. Then count the same number of degrees from the equator in the opposite hemisphere and the Anta>ci, of the place will be found. Next, Period, being situate on the same latitude, but on opposite meridians, set the hour pointer to the given meridian and rotate the globe by handle 180° in east longitude. Then the place on the globe below the same degree first assumed will be the Perioeci required. As the Antipodes lie opposite upon the globe, with feet to feet on opposite meridians and parallels of latitudes, the Antipodes will be found under the same degree of the oppo- site solar meridian, where at first the Antipodes stood. Solution.— First— What place on the globe is the Antojci of Quebec, 48° north? A. — Cape Blanco, in Patagonia. Second— What place on the globe is the Periocei of Toronto, 44° north ? A.— The Blue Lake in the West of China. Third— What place is antipode to Cape Horn, in South America ? A.— Cereina, in the north of Asia. Problem XXVIII. The time of a Lunar Eclipse being given, to find ail the places on the globe where it will be visible ? Rule.— Find where the sun will be vertical at the time of the moon's opposition ; bring 38 THE TEIIRESTHIAL GLOBE hc«u,„pl„c»t„tl,. »ola-,„eridian; th„„, a» the ™„ „,11 be vi,iH„ to all part, „( the h„.« exact, y„pp„s,to, the eolip» will be vi.iHe to all of the opposite o. UaA I, „ phe^e at any point of whieh the didemit phase., will bo seen. "cm.bpheio PltOBLEM XXIX When it i, 12 or noon at Monfeal. Canada, what is the civil ti,„e at .Sydnev Au,t,alia m.LK B,,n« Montreal to movable n.endian for the day. fix the hour vernierl nerf ' a.an plane ; hen keep n.eridian fixed, and turn the globe by the handle till .Sidney i b SilytZ ■"'«»- ''-'■^--V"-»P»int-ithere.«t or we,t will sho t e' i ' Ll'ts of tllO ime of an inisphere ITS USKS IN OKOGRAPHY. 39 Australia, to meri- y is be- llow the SECTION IV. SOME ADDITIONAL EXPLANATIONS ON THE IMPORTANT FUNCTIONS OF THE TWiLIGHT CIRCLE IN THE STUDY OF THE DYNAMICAL BRANCH OF PHYSICAL GEOGRAPHY. It is well understood, twilight is due to that optical property o'f the atmosphere, where- by, when the sun is below the local horizon, its rays by reflection and refraction are enabled to illuminate a portion of the sky beyond the twilight circle or the real geometrical boundary of the globes illumination. This partial illumination occurs as long as the su.. is less than 18° below the edge of the zone. As soon as it descends further then that distance twilight ceases, hence the globe viewed in the perspective from the outside, and from a point at right angles to the line joining the globe and sun, it will present the following appearances : It will have a brilliant, half illuminated hemisphere towards the sun, then a baund or zone of faint light, named twilight, IH" or about 1250 miles wide on the globe's surface, and lastly a large portion of a half hemisphere^, m t-Sl darkness. Now in the daily rotation of the earth every portion except the two Frigid zones passes through the twilight phase twice in every rotation of the globe. Hence very great differences occur in the duration of twilight according as the place passes below the solar horizon perpendicularly or obliquly. On looking at the apparatus it is obvious that when any place passe* perpendicularly it will reach the distance of 18° much sooner than where it passes very obliquely. In the study of this branch of topography it will always be very profitable to the pupil to illustrate the different conditions in which the globe and the twilight is placed in, and especially at the beginning of the various seasons of the year. For example, examine the position of the twilight at the two solstices. At this period it will be manifest that the zone will be concentric over every meridian on the earth at the noon passage, at right angles to them, and every place, when it comes to the twilight circle passes from below at the same instant of time, an occurence which takes place at no other time in the year. Hence from pole to pole on the earth every place on June 21st and Dec. 21 st have their shortest twi- lights, because every parallel of latitude moves through the zone at iught angles, which is the shortest path. 40 THK TEHRESTIUAL (iLOBE I Again it will next be observed, as a consequence of terrestrial curviture, the twilight lengthens as we proceed from the Equator to the poles. At the Equator every degree of longitude being equal to four minutes of time, and the zone 18° in width. It follows that the length of twilight will be 10 x 4 or 72 minutes of time. In acquiring a knowledge of the actual history of the difference of time any place is in twi- light, the following may be attended to. That at the parallel 72° north every place nouth is below the zone after sunset at the equinoxes, and consequently midnight darkness there en- tirely (eases, there being 12 hours of sunlight and 12 hours of twilight. Thus in both hemispheres the twilight varies from 72 minutes at the equator to 12 hours, at all latitudes north or south of 72 degrees ; that is within 18° of the poles. It is worthy to note here by bringing the sun's place to the northern tropic Gemini, the sun then has a declination of 23° 28'. Yet notwithstanding that obliquity, the duration of the twilight at the equator is practically the same as at the equinoxes, about 72 minutes. At the parallel of Toronto, for example, about 44° N., it will be found that the twilight has extended so obliquely on the globe when the sun is in Gemini—the time of the city's passage through it, is fully two hours and twenty minutes-so that real night, then, only lasts about three hours and twenty minutes. Moreover, north of the latitude b6° 30' at the above time in the year, the sun does not set during the twenty-four hours, so that there, there is neither night nor twi- light at the above day in the year. At the autumnal equinox, all the conditions as regards twilight, are identically the same as at the vernal equinox, excepting that the globe's axis, when viewed by the astrono- mical system of study, it inclines now to the left hand, instead of, as before, to the right of the ecliptic axis. In the annual progress of the twilight round the ecliptic axis it will be observed when the sun reaches the southern solstice (Sagittarius), the twilight is now in the equinoxial plane, and that all the illuminatintr phases observed in the summer of the northern hemi- sphere takes place now in the southern. From the parallel 66° 30' south to the pole it is constant day, and at all latitudes between 66° 30' south of the equator there are alterations of DAY, TWILKJHT and NIGHT. The reader who may now have attended practically to the foregoing explanations may quite readily discover with what ease and accuracy all the new problems can be solved by the Astronomical Globe, and we presume it is almost unnecessary to allude to its im- portance in the study of the globe's surface, since you cannot reason or point out intelli- gently any particular phase in the work without its use. In a g" it measure the terrestrial globe, without all the astronomical mechanical details, is very similar to a chronometer without either dial or index. In line, in revising and tracing the causes of the distribution ITS USES IN GEOGRAPHY, 41 he twilight •J degree of ollows that ice is in twi- ce NOIITH is IS there en- us in both ill latitudes 3te here by ition of 23° i equator is 'oronto, for lely on the i fully two hours and e year, the tit nor twi- tically the be astrono- le right of rved when equinoxial tiern hemi- pole it is alterations planations . be solved to its im- iut intelli- terrestrial ronometer stribution of light and heat upon the globe, which is principally the great object of this apparatus, with all the variations in the lengths of the days and nights in a year, with the observed variable periods of light and darkness within the Polar Circles. The following concjusious may be safely come to as to whence they arise : — First — To the orbital revolution of the globe around the sun in the ecliptic plane, and to the fact of the centres of the two bodies remaining always in the above plane. Second — To the inclination of the terrestrial axis to the globe's path in the solar system. Third — To the parallelism of the axis to itself, combined with the globe's axial rotation every 24 hour. In the study of this branch of geography with the Astronomical Globe it may be added all the geographical definitions should be fully riveted in the memory ; ami chiefly the mechanical portions which represent terrestrial phenomena, and such should be studied and taken from the apparatus itself. Also, it should be remembered, the full structure of terms used by geographers are of a mixed character, a portion being purely asti'onomical, viz., those relating to the circles of the sphere, and those which relate or describe the conditions of the surface of the earth. Hence the' use and necessity of uniting together the study of the two branches, Topography and Geographical Astronomy. The following are the most prominent definitions used in solving problems with the new globe, and they should all be closely traced on the apparatus and committed to memory. First — The great imaginary axis of the globe is a straight line or diameter, around which the whole mass turns once every twenty-four hours. Second — The poles of the GLOBE are the two places in its surface at the extremity of its axis north and south. Third — The North Pole determines the direction in which the axis points to in the Heavens, and the South Pole determines the opposite extremity. In the present age no telescopic star happens to be exactly over the two celestial points. Fourth — Meridians on the globes surface are hour circles, and when read on the globes equator, they are called right ascensions, but when referred to the ecliptic plane they indicate the ecliptic longitude. Fifth — The angles of right ascension are at the poles of the globe's axis and the LONGITUDE is at the poles of the ecliptic plane. Sixth — The Equator is a great circle equidistant from the two poles, it divide the globes into two hemispheres named after the poles. Northern and Southern Hemispheres. 1 THE TEIUIESTRIAL GLOBE .Sfvciitli-Parallels of latitude are circles parallel to the equator and they diminisli in |, ,1 diameter on the globe from the equator to the two poles. Bi-hth-Parallels of DECLINATION are circles parallel to the Equinoxial plane and they .liminish in diameter on the celestial sphere from tlie ecliptic plane to its two poles. I Ninth— The latitude of a place on the globe in degrees of arc is the distance of the place from the Equator North or South, hence all places north have north latitude, and .ill places south have south latitude. Tenth— The longitude of any place on the globe is its distance east or west from a given assume,! meridian Greenwich, (England) being now the prevailing prime meridian in popular astronomical geography, however for the Western Hemisphere, the Americans often for their maps and globes take the meridian of Washington. Eleventh— The declination of the sun is its distance in degrees of arc from the Equator, (often called the equinoctial or the line;, when it is north of this line or circle it is named North Declination, and when it it is south it is South Declination. Twelfth-The ecliptic PLANE or the orbit of the globe in the solar sy.stem, is the . Sun's apparent place among the stars in the mechanical arrangements of the new globe, the above orbit is represented by the great lithographic circle fixed to the tripod stand of the apparatus. In the construction of these globes the greatest care is laken t.T insure excellence of workmanship and accuracy in the different scientific adjustments required. The Manufact- urer therefore, is confident, that all educators who are desirous to procure improved school or library terrestrial globes will find that for giving accurate scientific exhibitions of ter- restrial phenomena the new Newtonian Globe excels all others which are sold either in Europe, England, or the United States. It may be mentioned in closing here, when the foregoing apparatus was fully completed it was expressly examined by the Hon. G. W. Ross, Minister of Education, who AT once ordered one for the Department, where it formed part of the school appliances which were sent from the Department to the Colonial and Indian Exhibition, London, and at the Exhibition the new Globe obtained a special notice of its merits, and also it was awarded a diploma and medal. ]■ ITS USES IN OEOGRAPUr. 1 43 SBLB0T Testimonials, The following Critical Notices have been selected from a minil.er the Inventor has received from different eminent educators and astronomers, who have liad an opportun- ity to examine the instrument: — Dearborn Oj!SERvatouy, Chicago, 111., April 25, 1885. I liave examined with great interest the Terrestrial Globe as arranged by Mr. M- Turnljull. It presents a number of novel appliances which make it of the greatest value as an educational instrument. The apparent annual motion of the sun, the change of the seasons— twilight, zone, and other terrestrial phenomena— are more clearly explained by its use than by anv other apparatus yet devised. , J " G. W. Hough, Director. Appended to the above was the following from Mr. Burnham, the great Chicago discoxever and measurer of the Binary systems at the Chicago Observatory : I have examined M. Turnbull's new Globe, and can fully concur in Professor Hough's high endorsement of it. It is truly a good thing, and should be extensively introduced. S. W. Burnham. The following notice appeared in the London " Monthly Observatory," edited bv the present Astronomer Royal of England :— Mr. Turnbull, of Toronto, has arranged a form of terrestrial globe which is highly useful for showing the changes of the four seasons-for finding the duration and posi- tion of twilight round the globe, and for solving a number of important new geographi- cal Y>rohlems.—Greenivich Monthly Observatory. Testimonial from Dr. Swift, Warner Observatory :— Mr. M. Turnbull, Dear Sir,— I have made a .somewhat critical study of the principles involved in the construction of your astronomical globe, and am free to give it my hearty and unqualified approval. By its use many abstruse truths may be very plainly demonstrated. The vaiied 44 THE TERRESTRIAL GLOBE phenomena produced by the inclination of the earth's axis to the piano of its ()rl)it, of which we are daily witnesses, though but few are able to understand, may, by means of this globe and its attachments, be made comprehensible by all. The geometrical scale of sines and cosines attached to the twilight circle over the inclined terrestrial axis, gives a useful and true illustration of the sunlight orbit of the globe's pol 3 round the ecliptic axis a devise highly useful to a draftsman in tracing the different phases that any parallel of latitude can take through sunlight and darkness during the year. Louis Swift, Director. Warner Observatory, Oct. 22nd, 1886. Testimonial from Prof. O. C. Wendale, of Cambridge Astronomical Observatory :— Mr. Turndull, I have examined the terrestrial globe as devised by you and find it is a highly useful article. It comprehends several novel devices quite unlike those of ordinary teruestrial globes, and by it several new problems may be solved, while for use in the school it must prove to be an excellent accessory. Harvard, Cambridge, Oct. 30th, 1886. O. C. Wendale. University College, Toronto Jan. 21st, 1886. Dear Sir, — Your improved globe was recently examined by Dr. McLellan, and a nuniber of prominent public school inspectors, and the opinion formed of it l)y all who took part in the examination was in the highest degree favourable, I know that the doctor him- self is of the opinion that one of your globes ought to be at least, in every County Model School in the Province, and that it would be of material service to have it introduced into as many as possible of the public and high schools. It would enable pupils readily to under- stand various important matters in physical geography, which, for the most part, they now really learn by rote. Yours very truly, George Paxton Young. Testimonial which was received from the late S. J. Watson, an eminent scientist and poet of Toronto : — I have carefully investigated the principles on which Mr. M. Turnbull has constructed his Astronomical Globe. These principles are at once natural, scientific, and easy of com- prehension. By this Globe the study of geography, which was before a task for the young, will now become a pleasure. The apparatus presents a complete and visible explanation of the physical phenomena which characterise the earth as a member of the solar system. From the time when globes first came into use for illustrating the science of geography to the present day no such invention as Mr. TurnbuU's has been given to the world. It will mark the beginning of a new era in the art of geographical and astronomical instruction. It is the work of a man who has been gifted with the rare faculty of translating great scientific knowledge into the shape of an apparatus which is a masterpiece of practical and beautiful mechanism. S. J. Watson, Late Parliamentary Librarian, Ontario.