( 2 4 l ) 
This Inconvenience is avoided by the revolving 
Oars ,• becaufe they take the Water "perpendicularly^ 
and enter far enough not to mifs it : And if the Water 
ihould happen to evade the Stroke, the Rowers would 
not be fo incommoded ; becaufe they would be fup~ 
ported at every Vibration , which is only of three 
Foot. Befides, in the Ufe of inclined Oars, more than 
hall the Time is loft, in railing and recovering the 
° ar > before they give the Stroke ; which makes the 
Veftel move by fits and jerks, fo that the People aboard 
feel (as it were) every Stroke of the Oars when they 
play ; whereas, the revolving Oars always move equal- 
ly, and fucceed one another without Lofs of Time ,* 
which makes the Veftel move uniformly, without af- 
fecting thole who are aboard. 
It is to be obferv’d too, that a Gaily built on pur- 
pofe for the Ufe of inclined Oars, would rrot be fo pro- 
per as another Veftel for perpendicular Oars ; becaufe 
the Gaily has a confiderable Length and but little Height 
above the Water. 
f • y -y 
) 
Having propofed this Invention to the Court of 
France , I was lent to Havre de Grace , to make a 
Tryal, which had the Approbation of the Intendant. 
He made his Report, That the Officers at firft object- 
ed to the Invention ,* but as for bis own part, the 
more particularly he confider’d it, the more he was 
convincdof its Ufefulnels. I was afterwards lent to 
Marfeilles , where I made feveral Tryals on board a 
Gaily ; the Swiftnefs of which was compar’d with that 
of another Gaily, equipp’d as ufual. M. de Chazelles , 
a Member of the Royal Academy of Sciences , and En- 
gineer of the King’s Gallies, had Orders to make his 
L 1 Obfer- 
