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 - zr ) 
— 1 ~ of an inch. But if, while the fcrew CD is turned a times 
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 
therefore of the handle ckl it will move upwards x - = ) 
of an inch. If then we luppofe the handle ckl to be 
a +a 11 
h inches long, the power gained by the machine will be as 
a +-a x 6,2832 b to unity. 
To illuftrate this by a particular example, let the fcrew cd 
have 10 threads in an inch, and de 1 1 : then, while the handle 
ckl is turned 10 times round, the point d will rife one inch 
above its former fituat ion. But at 10 turns it can only pafsover 
10 threads of the fcrew de, and confequently it will advance 
upon that fcrew of an inch. The point e therefore muft 
rife -f-rth 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 -j-To-th of an inch ; and if the 
handle be fuppoled half a foot long, the power, to produce an 
equilibrium, muft be to the weight as 1 to 1 10 x 6,2832 x 6 = 
4146,912, which is the very number exprefled by the general 
theorem, viz. a 4 - a x 6,2832 b , calling a—\o and b — 6. 
Now let us compare, according to the rules before laid down, 
this method of unng the fcrew with the common one. And, 
fir ft, in order to have the fame power by means of the common 
fcrew that is exerted by this machine, it muft have a number of 
threads 
