( 48 ) 
be the Motion fwift or flow, in any meafured Di- 
ftance, the Number of Revolutions will be equal. 
This is the Machine which I firft tried on the Ca- 
nal in St. Jameses Park^ and with this it was, that 
I made my Obfervations on the Tides in the River 
fhames^ as they appear in the Philofophkal f ran/- 
anions for the Months of March and ^pr 'tl 1716 ; 
which I chofe the rather to do, in regard I found it 
to anfwer very well in all my Experiments. And I 
am yet of Opinion, that it would be an ufeful Inftru-^ 
ment tcv determine the Strength of the Tides on our Sea 
Coaft, which if marked in our Charts, might prove 
advantageous ’ to our Commerce.. But confidering, 
that though this Projedion might be ferviceable in 
Barges, Pleafure-Boats, or other Veflels, in fair and 
moderate Gales of Wind, yet it might prove ufelefs 
in boifterous and ftormy Weather, and in long Voy- 
ages, when it might be choaked with Weeds ^ I there- 
fore fixed to my other Invention the Fork, which is 
contrived in fuch a Manner, that I will even yet be 
fo bold as to affirm, it ffiall determine the Ship’s Way 
in a Storm, or when fhe is fcudding before the 
Wind, when the Log is incapable of it. As the 
Canal would not allow me to try, with any Cer- 
tainty, my Iron Forks there,, I was obliged to have 
fome made of lighter Materials, which feemed' to an- 
fwer fomewhat near the Truth,, and made me fo fan- 
guine as to believe, that they would have an equal 
Number of Revolutions in the fame Diftance, even 
though the Motion of the Boat was fwift or flow be- 
tween Mark and Mark. • I muft here do my worthy 
Friend Dr. D^faguVms (who frequently honoured 
me witi^ his Company in the Experiments of the 
3 aforefaid 
