nons. 



284 1 ON THE PLANET CERES. 



Method of ufing The above machine affords a delineation which is ftrictfy 

 ru£"o 8 r r taking daccurate: but l take this opportunity of mentioning one itUI 

 views, &c. more portable, though lefs exact, which may be ufed in taking 

 fmall (ketches in the field'; where the table, and fixed meet of 

 paper cannot always be fuppofed at hand. I do not know 

 the contriver. It is merely a fcrait flat ruler, having a divi- 

 fion of inches and fmall parts (or any other diviiion) on its 

 edge. A firing is fattened to the middle of the ruler by paf- 

 iing it through a hole, and tying a knot on the other fide ; 

 and at the other end of the firing there is a (mall bead or knot 

 to be held in the mouth. The length of the ftring may be 

 adjufied at pleafure; and when the ruler is ufed, it is held up 

 at right angles to the flretched ftring, fo that its edge, as feen 

 by one eye, may apply to any two objects ; between which it 

 will fliew the diflance to be afterwards transferred upon the 

 paper by a fcale, or by eflimate. 

 Farther obferva- In this ufe of a graduated rule, it is mod convenient and 

 accurate to felect fome one object in the picture for the point 

 of fight, and to meafure all the diftances from thence from the 

 middie or beginning of the divifions where the direction of the 

 fight is at right angles to the rule. And as this fimple in- 

 flrument does not give the inclinations, it may be befl always 

 (o meafure parallel or perpendicular to the horizon, and efli- 

 mate the reft. Indeed, the contrivance muft be confidered 

 only as a fubflitute for the ufual method of eflimating, and may 

 be principally ufeful to aflift in acquiring a correct judgment in 

 this refpect. W. N. 



IX. , 



Concerning the new Planet Ceres. In a Letter from the Rev. 

 William Pearson, including an Ext raft of a Letter from 

 the Baron de Zach to Mr. Edward Troughton. 



To Mr. NICHOLSON. 

 & I R, 



Parjbn's Green, March 9, 1302. 



Intrftduaory re- IAS the difcovery of the new planet Ceres is an event which 

 account of The" nas a l rea( ty engaged the attention of the principal aftronomers, 

 manner of apply- of Europe, and will contmue to be a fubject of difcuflion 

 ing obfervations. until 



