6 o 
Mr. hunter on a new Method 
point e will move downwards of an inch, and the refult 
of both motions will be to lift the point e upward ( i - = ) 
— ~~ of an inch. But if, while the fcrew CD is turned a times 
* + 1 
round, de be kept from moving, the effect will be the fame as 
if it had moved a times round with CD and been a times turned 
back, that is, it will advance —7— of an inch. At one turn 
7 7 < 3+1 
therefore of the handle ckl it will move upwards x ~ = ) 
— ~ of an inch. If then we fuppofe the handle ckl to be 
h inches long, the power gained by the machine will be. as 
a* -\-a x 6,2832 b to unity. 
To illullrate this by a particular example, let the fcrew CD 
have 1 o threads in an inch, and de 1 1 : then, while the handle 
CKX is turned 1 o times round, the point d will rife one inch 
above its former Situation. But at 10 turns it can only pafs over 
1 o threads of the fcrew de, and confequently it will advance 
upon that fcrew *.iths of an inch. The point e therefore mud: 
rife of an inch, that the point d may have room to rife a 
complete inch above its former place : therefore, at one turn of 
the handle, the point E will rife -^th of an inch ; and if the 
handle be fuppofed half a foot long, the power, to produce an 
equilibrium, mud: be to the weight as 110110x6,2832x6 = 
4146,912, which is the very number expreded by the general 
theorem, viz, a -{-a x 6,2832 b, calling a~io and b~ 6 . 
Now let us compare, according to the rules before laid down, 
this method of ufmg the fcrew with the common one. And, 
fird, in order to have the fame power by means of the common 
fcrew that is exerted by this machine, it mud have a number of 
threads 
