and Dippings of the Needle 5 in different places , and in the 
fanae place , at different times : The Winds 5 Weather, and 
Tempers of the Seafons every where : The great Depths, 
Ground, and Vegetables at the bottom of the Sea; The vari- 
ous Degrees of Saltnefs of the Sea-water , in feveral places , 
and at feveral Depths at the fame place. If befides Aflrono- 
mical things , to be hereafter lookt into, the following Expe- 
riments be carefully made y and Direflions obferved by as many 
Ingenious Perfons, as have opportunity , it may fairly be hoped, 
that from multitudes of Experiments and Gbfervations , fuch 
Rules may be framed 5 as may be of ineflimable ufe for Seamen. 
To which pu^pofe, the Rffjai Society having fome years ago, 
ordered t;hac Emnent Mathematician Mafter , oneoftfeir 
Fellows zniGeomtrfPtoitfforofGreJham CoSed^e (fince decea- 
fed 5 to the great detriment of the Common- wealth of Learning) 
todrwiwup fome Diredions for Seamen, the better to capacitate 
them for making fuch Obfervations abroad, as might be perti- 
nent and fuitable to the purpofes above-mentioned 5 fuch Directi- 
ons were drawn up accordingly , and foon after printed in 
Numt. 8. of thefe T ranfaBims, But , further to encourage 
and facilitate the Work of thofe , that fhall be engaged to put . 
them into piadice, it was thought fit, that what of this Kind 
was heretofore but barely propofed , fliould now be publilht 
with ample and particular Explanations 5 and conliderable Additi- 
ons which done, a good Ntober of fuch printed Copies is , by 
the Care, and at theExpences of thei?. Societf^ to be lodged with 
ihtMsiil^roi Trimty-Hofife^ to be recommended to fuch , as are 
bound for far Sea- Voyages , and fball be judged fit for the per- 
formance: who are alfo to be defired , to keep an exa(5H)///ry of 
fuch Obfervations and Experiments , and deliver at their return a 
fair Copy thereof to the Lord High Admiral oi England , his Roy- 
al Highnefs the Duke of Yffrk , and another to Trinity- Um[e > to 
be perufed by the faid Society . 
