Additional Notes. 415 



I see but one fault in this instmment, nnd that is, tliat lhre« 

 feet radius in this has a graduation no larger than a qij^drant ijf 

 eighteen inches radius. I hope Dr. Halley has received a more 

 fall account of this from J. Logan, esq., therefore I shall add no 



more than that I am, gentlemtn. 



Yours, iVc. 

 T. GODFREY. 

 Philadelphia, Nov. 9, 1734. 



Page 529. Extracts from "A further Account of Thomas God- 

 frey's Improvcmait of Davis's Quadrant transferred to the Mari- 

 ners Boiv.'* 



Being informed that this improvement, proposed by Thomas 

 Godfrey, of this place, for observing the sun's altitude at sea with 

 more ease and expedition than is practicable by the common in- 

 strument in use for that purpose, was last winter laid before tha 

 Koyal Scx:iety, in his own description of it, and that some gentle- 

 men wished to see the benefit intended by it more fully and 

 clearly explained, I, who have here the opportunity of knowing 

 the author's thoughts on such subjects, being persuaded, in my 

 judgement, that if the instrument, as he proposes it, be brought 

 into practice, it will in many cases be of great service to naviga- 

 tion, have therefore thouglit it proper to draw up a more full ac- 

 count of it than the author himself has given, with the advan- 

 tages attending it, which if approved of by better judgements, to 

 whom what 1 otfer is entirely submitted, it is hoped the use of it 

 will be recommended and further encouraged, as well as the au- 

 thor. The use of the improvement, witli its conveniences, a 

 also a description of it, are as follows. 



[Then follows a repetition of the account of Godfrey's having 

 studied — what occurred to him about tlie importance of knowing 

 the latitude and longitude of a ship's place, &:c., which I do nut 

 transcribe, as it is long, and not to your purpose. 



E. II.] 



Pa^e 532.~Some masters of vessels who sail from hcnco ta 

 the West Indies liave got some of them* made, as well a.s they 

 can be done here, and have found so great an advantage in the 

 facility and in the ready use of them in those southerly latitudes, 

 that they reject all others. And it can scarce be doubted, but 

 when the in^iruraciit becon^es generally knu%vn, it may, uixm 



* Goduey'j in«trument-w 



