ue se ( Qo f} f ae. 
N°. X. 
MeEmoIR of JONATHAN WILLIAMS, on the ufe of the 
Thermometer in difcovering Banks, Soundings, Gc. 
Read Nov. ff HLAV E hitherto delayed making a public com- 
ras munication of my fea journals, from an appre- 
henfion of being thought too forward in calling the attenti- 
on of the Philofophical Society to the fubje&t of them; but 
being imprefled with a belief; that by noticing the changes 
in the heat of the fea water, a navigator might ayare know 
when he is in foundings, and thereby be able to efcape the 
dangers ariling from unexpected currents, and erroneous 
reckoning, I cannot think mytelf juftifiable in longer he= 
fitating to fubmit my remarks to their learned and judici~ 
ous examination, 
This fenfe of duty is ftrengthened by the recolleCtion of 
many melancholy inflances;where mariners, in full confi- 
dence of being);at a diftance from land, have, with 
crouded fails, raalineds: on to defiruction; and f was once 
within half an. hour’s time of being fifswrécked on, the 
rocks of Scilly, dls, the return of day prefented to our 
view the dreadful fate we had fo narrowly efcaped. 
If it fhould be found that the ufe of the thermometer would 
be an improvemeatin theart of navigation, I fhall be abun- 
dantly. rewarded. by the refleGtion of having contributed to 
the fervice of humanity, which is the common caufe of all 
men. If it fhould, on the contrary, appear that Iam mif- 
taken, either in the faéts or the conclufions deduced, I 
truft that the defire of doing good, the only motive that 
actuates me, will meet with indulgence from every can= 
did mind. 
In the months of Auguft aly: September, 1785. I was 
a fellow paflenger with the late DoGtor Franklin from Eu- 
rope to America, and made, under his direction, the ex- 
periments 
