[ r 5S ] 
errors in making the experiments : but as thofe 
experiments, as well as thofe of the greateft load, all 
deviate the fame way ; and alfo coincide with fome 
experiments communicated to me by Mr. Roufe 
upon the refiftance of planes ; I am led to fuppofe a 
fmall deviation, whereby the load falls fhort of the 
fquares of the velocity ; and fince the experiments 
No 3 and 4. are mod: to be depended upon, we 
‘mud: conclude, that when the velocity is double, the 
load falls diort of its due proportion by T ~, or, for 
the fake of a round number, by about part of the 
whole. 
Maxim 3d. The effects of the fame fails at a maxi- 
mum are nearly , but fomewhat lej's than , as the 
cubes of the velocity of the wind. 
It has already been proved, Maxim id:, that the 
velocity of fails at the maximum , is nearly as the ve- 
locity of the wind ; and by Maxim 2d, that the load 
at the maximum is nearly as the fquare of the fame 
velocity : if thofe two maximums would hold pre- 
cifely, it would be a confequence that the effedt 
would be in a triplicate ratio thereof: how this 
agrees with experiment will appear by comparing 
together the products in col. 8. of tab. 4. wherein 
thofe of N° 2. 4. and 6. (the velocity of the wind 
being double) ought to be o&uple of thofe of N« 1. 
3 . and 5. indead of which they fall diort, N° 2. by y 
No 4. by Vo, an d No 6. by ~ part of the whole. 
Now, if we rely on No 3. and 4. as the turns of the 
fails are as the velocity of the wind ; and dnee the 
load of the maximum falls diort of the fquare of the 
velocity by about -3 part of the whole : the produdt 
X 2 made 
