GLOBE. 



ftandinn- direaiy over the north pole of tlie ecliptic, and horizon is moved in reAifying it for different latitudes. To 

 perpendicular to that part of the furface of the jrlobc. On the middle of the femi-circle is fixed a pin, which always 

 iln/nin are two moveable collets at D and H, to which 



this pin are two moi 

 are annexed the quadrantal wires N and O, carrying two 

 little balls rcprcfenting the fun and mooi.. The collet D is 

 fixed to the circular plate F, on which are engraven the 29,; 

 davs of the moon's age, beginning under the wire N, which 



keeps in the zenith of the horizon, and on this pin the qua- 

 drant of altitude q turns ; the lower end of which, in all 

 pofitions, touches the horizon as it is moved round the fame. 

 This quadrant is divided into 90 degrees from the horizen 

 to the zenithal pin on which it is turned, at 90. The great 



wire as it turns round, car'Jies with it the plate F. Thefe flat circle or plate A B is the ecLptic, on the outer edge oF 



wires are fixed or (lackened by the fcrew G, and the two which the i'lgns and degrees are laid down ; and every 



little balls are made to rife and fet at the fame time and on fifth degree is drawn through the reil of the furface of 



the fame point of tk- horizon, for the day to which t_bey this plate towards^ its centre. 

 are reftilied, as the fun and moon do in the heavens. 



On this plate are feven 

 The grooves, to which feven httle balls are adjullcd by Aiding' 



gxwu>. ... .ight ang 

 over S to ftand upright upon it : from this line, on the con- 

 vex edge, are drawn the t,\ degrees of the moon's latitude 

 on both fides of the ecliptic ; and when this piece is let up- 



rately ftampt with the following charaftcrs : g', ^, $,0, 

 J, If, Ij . This plate or ecliptic is fupported by four 

 ftrono- wires, having the lower ends fixed into the pedeftal 



risjht on the globe, its graduated edge reaches to the moon at C, D, and E, the tourth being hid by the globe. The 

 on the wire O, bv which means (he is eaiily adjuiled to her ecliptic is inclined 23^ degrees to the pedeftal, and is there- 

 latitude found by an epliemeris. The horizon of this globe fore properly inclined to the axis of the globe \\hich ftands. 

 is fupported by two femi-circular arches, becaufe pilh-.r? upright on the pcdellal 



would' flop the progrefs of the balls, when they go below 

 the horizon in an oblique fphere. This globe is rectified by 

 elevating the pole to the latitude of the place, bringing the 

 fun's place in the ecliptic for the given day to the brazen me- 

 ridian, and fetting the hour-index to twelve at noon ; then, 

 fetting the fun direftly over his place in the meridian, and 

 the nwon over her place in the echptic, by fixing her wire 



To retiify thh miuhine. — Set the Sun, and all the planetary 

 balls, to their geocentric places in the ecliptic for any given 

 time, by an ephemeris ; then fet the north point of the ho» 

 rizon to the latitude of your place on the brazen meridian, 

 and the quadrant of altitude to the fouth point of the ho- 

 rizon ; which done, turn the globe with its furniture till the 

 quadrant of altitude comes right againft the Sun, I'/'c. to his 



under the number that exprefles her age for that day on the place in the echptic ; and keeping it there, fet the hour in. 



plate F; and, laftlv, laying the curved edge of the pafte- dex to the XII. next the letter C. 



boai-d S over the ecliptic below the moon, andadjufting the By this machine the following problems, as well as many 



moon to her latitude over the graduated edge of the pafte- others, may be refolved. 



board. Havino- thus reftified the globe, turn it round, and To Jiiul the amplitude, meridian alt'itiides, and times of rlfn^, 



oblerve on what point of the horizon the fun and moon balls cidmiiiating, and fetting of the fun, moon, and planets. — Turn the 



rife and fet ; for thefe agree with the points of the compafs globe round eaft ward, or according to the order of the figns ; 



on which the fun and moon rife and fet in the heavens on the and as the eaftern edge of the horizon comes right againlt the 



given day : and the hour-index fhews the times of their fun, moon, or any planet, the hour-index will ftiew the time 



rifine and fetting, and alfo the time of the moon's paffing of its riling ; and the inner edge of the ecliptic will cut its 



over the meridian. This globe is alfo contrived for exhibit- rifing amphtude in the horizon. Turn on, and as the quad- 



J!i<T the phenomena of the harveft-moon, &c. Phil. Tranf. rant of altitude comes right againft the fun, moon, or pla- 



vo ,g„_ gi-t. 21. in vol. xhv. p. 535, or Fergulon's Aftron. nets, the ecliptic cuts the meridian altitudes in the quadranti 



201^ and the hour-index fhews the times of their coming to the 



Globe Dial/im;. See Di.\li,ixc. meridian. Continue turaing, and as the weftern edge of 



Globe.s P^/t;;/, are thofe with the improvements of Mr. the horizon comes right againft the fun, moon, or planets, 



■Neale for which he obtained bis majcfty's letters patent; their fetting amplitudes are cut in the horizon by the ecliptic ; 



bv means of which he folves feveral aftronomical problems, and the times of their fetting are fhewn by the index, on the 



which do not admit of folution by the common globes. hour-circle. 



GloBE Planetary, is a mr.chine contrived and defcribed To find the altitude and azimuth of the fua, moon, and planets, 



■bv Mr. Fergufon ; in which T [Plate XV. Aflronomy, at any time of their being above the horizon. — Turn the globe 



V 12'?') is a terreftrial globe fixed on its axis ftanding up- till the index comes to the given time in the hour-circle ; and • 



rfo-ht on the pedeftal C D E, on which is an hour circle, 

 having its index fixed on the axis, which turns fomewhat 

 tightly in the pedeftal, fo that the globe may not be liable to 

 fhake ': to prevent which, tlie pedeftal is about two inches 

 thick and the axis goes quite through it, bearing on a 

 Ihoulder. The globe is hung in a graduated brazen meri- 

 dian, much in the ufual way ; and the thin plate N, N E, 

 E, is a moveable horizon |;raduated round the outer edge, 



keep the globe fteady, and moving the quadi-ant of altitude 

 to each pkmet refpectively, the edge of the ecliptic will cut 

 the planet's mean altitude on the quadrant, and the cptadrant 

 will cut the planet's azimuth, or point of bearing on the ho- 

 rizon. 



The fun^ s altitude being given at any time cither before or 

 aft.r noon, to find the hour of the day, and the variation of the . 

 compafs, in arty ino'uin latittuk. — With one hand hold the edge 



for fhewin<^ the bearings and amphtudes of the lun, moon, of the quadrant right againft the fun ; and, with the other 

 and T)Iane?s. The brazen meridian is grooved round the hand, turn the globe weftward, if it be in the forenoon, or 

 outer edee • and in this groove is a (lender femi-circle of e.iftw.iid if it be in the afternoon, until the fun's place at 

 brafs the ends of which are fixed to the horizon in its north the inner edge of the ecliptic cuts the quadrant in the fun's 

 atJid fouth poiats ; this femi-circk Hides in the groove as thq obferved altitude ; and then the liourindex will point out 



7 *^? 



