T,8>2 11V1JK()(;K.\I>J11':k's DI-^PAKTMKNT of the ADMIRAL'J'V. 



Many of our men that kept journals iniijuted it to the half-niinule 

 glasses, and indeed we had not a good ,ij;lnss in the ship hesicie the half- 

 watch or two-hour glasses. As for our half-minute glasses we tried them all 

 at several times, and we found those that we had used from Brazil as 

 nuich too short, as others we had used before were too long, wdiich might 

 well make great errors in those several reckonings. A ship ought there- 

 fore to have its glasses very exact ; and besides, an extraordinary care 

 ought to be used in heaving the log, for fear of giving too much stray-line 

 in ;i moderate gale: and also to stop (piickly in a brisk gale, for when a 

 ship runs 8, 9, or 10 knots, half a knot or a knot is soon run out. and 

 not heeded. But to prevent danger, when a man thinks himself near 

 land, the best way is to look out betimes and lie by in the night, for a 

 Commander may err easily himself, besides the errors of those under him. 

 tho" never so carefully eyed. 



Another thing that stumbled me here vv.is the variation, which, at ibis 

 time, by the last ami)litu(le I had found to be but 7 deg. 58 niin. W. 

 whereas the variation at the Capv ( from which 1 found myself not 30 

 leagues distant) was then computed, and truly, about 11 deg. or more. 

 .'\nd yet a while after this, when I was got 10 leagues to the Eastward of 

 the Cape. T found the variation but 10 deg. 40 min. W., whereas T should 

 have been rather more than at the Cape. These things, T confess, did 

 puzzle me. Neither was 1 fully satished as to the exactness of the taking 

 the variation at sea; for in a great sea. which we often meet with, the 

 Compass will traverse witli the motion of the ship, besides the ship may 

 and will deviate somewhat in steering, even by the best Helmsman. And 

 then when you come to take an A/'innith, there is often some difference 

 between him that looks at the coni])ass. and tlu' man that takes the Alti- 

 tude height of the sun, and a small error in each, if the error of both 

 should be one way will make it wide fif any great exactness. But what was 

 mo.st shocking to me, T four.d that the variation did not always increase 

 or decrease in proportion to the degree of longitude East or West, as T 

 had a notion they might do to a certain number of degrees of variation 

 east or west, at such or such particular meridians. But finding in this 

 voyage that the difference of variation did not bear a regular jiroptniion 

 to the dift'erence of longitude, 1 was much pleased to see it thus observed 

 in a scheme shown me after my return home, wherein are represented the 

 several variations in the Atlantic Sea, on both sides of the luiuator : and 

 there, the line of no variation in that sea is not a meridian line, but goes 

 very oblique, as do tliose also which show the increase of variation on ea9h 

 side of it. in that drauglit there is so large an advance made as well 

 towards the accounting for those seemingly irregular increases and 

 decreases of variation towards the S.E. coast of .\merica, as towards the 

 fixing a general scheme or system of the variation everywhere, wdiich 

 would be of such great use in navigation, that I cannot but hope that the 

 ingenious author, Capt. llalley, who to his profound skill in ;dl theories of 

 these kinds, hath added and is adding continually personal experiments, 

 will e'er long oblige the world with a fu'ler discovery of the course of the 

 variation which hath hitherto been ;i si'crrt. h'or my jiart, 1 profess ni\self 

 un(iualified for offering at any thing of a general scheme; but since 

 matter of fact, and whatever increases the history of the variation, may 

 be of use towards the settling or confirming the theory of it, 1 shall here 

 once for all insert a Table of all the Variations 1 observed beyond the 

 Equator in this voyage, both in going out, and returning back; and what 

 errors there may be in it I sliall leave to be corrected by the observations 

 of others. 



1 add his little i)ioliire ui the ."-^toniiy I'etrel. for the sheer 

 beauty of it : — 



The petrel is a bird \-n>l nnich unlike a swallow but smaller, and with a 

 short tail. 'Tis all over l)lack, except a white si)ot on the rump. They 



