GLOBE TIME-PIECE. t^ 



Briftol, February 28tli, 1800. 

 Respected Sir, 



Read ApriiTT is HOW a confiderablc time fince I have 

 4th, 1800. j|_ made foine iinprovements in different mathe- 

 matical inftruments and machines ; which I did not, 

 however, think of fufficient confequence to prefeut to 

 the fociety : but having not long iince fhewn them to 

 fome of my friends, they have induced me to prefent 

 the inclofed drawing and defcription of my globe time- 

 piece. If this fhould meet with a favourable reception, 

 I fhall be encouraged to bring forward fome others 

 which I now have by me. The globe time-piece, I 

 have not adlually conftrudled, but have begun it, and 

 when finifhed will with pleafure exhibit it to the fociety. 

 I 'remain, Sir, 



Refpedlfully your humble fervant, 



BURGISS ALLISON. 



Thomas Jefferson, Esq^^ Prefident of 

 the American Philofophical Society. 



AA is a terreftrial globe of any convenient fize, fay 

 8 inches in diameter, then will the hours marked on the 

 equator be about i inch afunder. Within the globe is 

 the movement of a fpring time piece by which the globe 

 is turned round on its axis Once in 24 hours. BB is 

 a flat hoop of brafs in which the globe turns as it does 

 in the brazen meridian of common globes, and which 

 ferves to point out the hours as they pafs in fucceffion 

 under it. CC is a light hoop with the minutes marked 

 on it, and which may be carried round by a femicir- 

 cular wire attached to a cannon moving round the north 

 pole, and thence communicating with the internal move- 



L 2 ment 



