Neiu-invcnted AJlranomical Injirument. 83 



Piazzi would be made by fome diligent aftronouier ; and 

 the opinion has been lately revived by Mr. Capcl Lofft, a 

 gentleman well known for his attachment both to the fei- 

 ehces and the mufes. In the New London Review for March 

 1800, this gentleman, in a critique on the Athenian Letters, 

 ventured to ofier fome conjefturcs refpefting an intermediate 

 planet between Mars and Jupiter, the coincidence of which 

 with the new difcovcry is very remarkable. He fuppofed that 

 the diftance of the intermediate planet from the Sun would 

 be to that of Mars, either as 33 to 15, or as 20 to 15, the 

 midway between which correiponds nearly with the faft. 

 With refpcdl to its diameter, he conceived it might be to that 

 of Mars, as that of Mars to the diameter of the earth; and 

 then being not much more than half the diameter of Mars, 

 and at five times the perigean diftance, it would be feenfrom 

 the Earth under an angle of 2.' " or 3", while Georgiuin 

 Sidus would appear under an angle of 4". Thefe lucky 

 conjeftures were drawn from a certain kind of Pythagorean 

 harm'jny^ And are ingcnioufly defended in the Keview juft 

 mentioned." 



XV. Dcfcr'ipUon of a new -invented AJlronomical InJlrU' 

 ment, fur placing Globes in a frcper Sitr/ation, by means of 

 the Sim, zc'ltho7/t the Help of a Magnetic Compajs, or other 

 Injirument. By Mr. E. M. Forster *. 



I 



T confifis of a brafs circle, C,C, (Plate TT. fig. 2 and 3.) 

 made to fit the furface of a twelve-inch globe. Acrofs this 

 circle is a brafs bar, B, B, arched on the under part, to fit 

 the curve of the globe, and flat at the top. The fides of this 

 bar are graduated, anlw.ering to ten degrees of the ecliptic ; 

 and the under part is chamfered fo, that the edge may be 

 very narrow which lies over the ecliptic, when in ufe. On 

 the flat top of the bar is a fniall hole, with a metal pin S, 

 ferving as a Jlyle to call a fiiadow. The part which re- 

 ceives the fliadow is painted a dead-white, to prevent the 

 dazzling which the brafs alone would have occafioned. 



This little inftriuncnt, which may be called a folar ftyle, 

 was made under my direction by Mr. Blunt of Cornhill. 

 Method of ufng the Injirument . 



Find the fun's place in the ecliptic, by an almanac, (or 

 on the wooden lujrizon of the globe, if marked there,) then 

 place the inltrument in fuch a manner on the furface of the 

 plobe that the |iin ov Jljle be exai^tly over that pi ice on the 

 ecliptic. iJaving done this, turn the* globe uilo fuch fk 



• Ccmn umc-.rrtl ty the uuil.'.r. 



F 2, iiluation 



