478 Additional Noks. 



by the common Instrument in use for that purpose, was last 

 winter laid before the Royal Society, in his own description 

 of it, and that some gentlemen wished to see the benefit in- 

 tended 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 judgment, that if the 

 instrument, as he proposes it, be brought into practice, it will, 

 in many cases, be of great sei-vice to navigation, have, there- 

 fore, thought it proper to draw up a more full account of It 

 than the author himself has given, with the advantages attend- 

 ing it, wliich, if approved of by better judgments, to whom 

 what I offer is entirely submitted, it is hoped the use of it 

 ■will be recommended and further encouraged, as well as the 

 author. The use of the improvement, with its conveniences, 

 as 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 the importance 

 of knowing the latitude and longitude of a ship's place, &c. 

 which I do not transcribe, as it is lengthy, and not to your 

 purpose. E. H.] 



Page 532. — Some masters of vessels who sail from hence 

 to the West-Indies have got some of them* made, as well 

 as they can be done here, and have found so great an ad- 

 vantage 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 instrument becomes gene- 

 rally known, It may, upon the Royal Society's approbation, 

 if the thing appears worthy of it, more universally obtain in 

 practice. It is now four years since Thomas Godfrey hit 

 on this improvement: for his account of it, laid before the 

 Society last winter, in which he mentioned two years, was 

 Vv'rote in 1732; and In the same year, 1730, after he was 

 satisfied in this,t he applied himself to think of the other, 

 viz. the reflecting instrument by speculums for a help in the 

 case of longitude, though It is also useful in taking altitudes; 

 and one of these, as has been abundantly proved by the 

 maker, and those who had It with them, was taken to sea, 

 and there used In observing the latitude the winter of that 

 year, and brought back again to Philadelphia before the end 



* Godfrey's instruments. 



t That is, I suppose, being " satisfied," that he had made a real im- 

 provement in the Quadrant E. H. 



