[ 163 3 



LETTER V. 

 XX\ai Wright on measuring the Meridian— 'Wrigut, 

 • Wren and Wilkins on an Universal -^^e^""'"^— j • ^"^ ^ ; 



TisTA Porta on the Reflection of Heat, Cold and Sound 



from concave Mirrors. 

 Ego sane non minoris aestirro, imo multo magis admiror, inventorem 



Tyrrprimum, quam vel centenos artifices alios, qm,scquent>bus sa=cu- 



' ^ G. Galiljei Syst. Cosrn. ed,,i699. p. S*"*- 



SIR, 



In addition to mv four communications, on the invention 

 of the td^scope, &c., I mtended to have offered you som 

 reflections on the adoption and execution ot the method. 

 aTey trkenmFraiJ, for establishmp natural standa.^ 

 of weishts and measures. But, atter a good deal ot 

 lughfand a careful perusal of/h;/;^^^^ ^\f 3^^- 

 i^issioners in the Memoires de I' Institict «; J^^Sf^^^^ '^^^.^ 

 iect appears to me to present such amp e scope tor me>e 

 i^lS that I find It .'ould be impossible for me ^^^^J 

 mv doubts, without exciting controversy. lho=e doubts 

 "Le in my mind, upon reading the ^^-'^ ^jf f-^^^ 

 GalHeo's Systema Cosmicum ; Jurm's annotations on the 

 4 h chapter^f iX^.^Geograplua Generaks of f--^-^^ ^f 

 the 20th proposirion of the 3d book ot i\i^ Pnncipa, 

 ,M^TsJnd\ not to mention the late correction ot the 

 lrsurements,of Maupertras U. by M^^-«^-.-nd 



other Swedish astronomers, ^^'1^^'^^\.I>„^^' "°\'X 

 Having no wish to propagate my scepticism, oi to re du 

 "incurable bv contestation, I shall content mysclt with 

 oSvou the two following extracts; leaving you and 

 ;ourSligent readers to compare them with the Repo 



:^!lf ison w.th ttif per^r^s ofj^gc^jiaus ^^^^^^/^ 



^r 'ZJt'^^^^ Measures, Loi^;n 

 1788 • E^sai sur les Folds el Ics Mesures,y^xM.Be,- 



Weiffhsand Measures, m the Philosophical T.ansact^ons 

 for nOS It has been said, that our great vuiinaual, 

 7oUL,dixl more for the English language, than some 



. Author of a copious, and. as I am told, a very good book on clock- 

 and watcl.-v.ork, lately published at Pans, .u 3 voh. 4^. _ 



Ij 2 for«igti 



