FOR 
FOR 
* 
np faster with a burden of 100Z6, weight, 
than a horse that is loaded with 300lb . ; a 
difference which is owing to the position of 
the parts of the human body being better 
adapted to climb than those of a horse. On 
the other hand, the best way of applying 
the force of a horse, is in a horizontal direc- 
tion, wherein a man can exert least force ; 
thus a man weighing 1401b., and drawing a 
boat along by means of a rope coming dver 
his shoulders, cannot draw above 27 lb., or 
exert above one-seventh part of the force of 
a horse employed to the same purpose. The 
very best and most effectual posture in a 
man, is that of rowing, in which he not 
only acts . with more muscles at once, for 
overcoming the resistance, than in any 
other position ; but, as he pulls backward, 
the weight of his body assists by way of 
lever. 
Force accelerative, or Retardive Force, is 
that which respects the velocity of the mo- 
tion only, acceleraling or retarding it; and 
it is denoted by the quotient of the motive 
force, divided by the mass or weight of the 
body. So, if m denote the motive force, 
and 6 the body, or its weight, and /the ac- 
celerating or retarding force, then is/as 
Again, forces are either constant or varia- 
ble. Constant forces are such as remain 
and act continually the same for some de- 
terminate time. Such, for example, is the 
force of gravity, which acts constantly the 
same upon a body, while it continues at the 
same distance from the centre of the earth, 
or from the centre of force, wherever that 
may be. In the case of a constant force F, 
acting upon a body b, for any time t, we 
have these following theorems ; putting/ =; 
the constant accelerating force = F -7- b ; 
vs= the velocity at the end of the time t ; 
s = the space passed over in that time, by 
the constant action of that force on the 
body : and g — 16 /, feet, the space gene- 
rated by gravity in 1 second, and calling 
tire accelerating force of gravity 1 ; then is 
* = J to = gffi = ~ v = 2 gft 
= v /4 gfs) 
v * 
4 gs' 
2 s 
v 
Forces variable, are such as are conti- 
nually changing in their effect and inten- 
sity ; such as the force of gravity at differ- 
ent distances from the centre of the earth, 
which decreases in proportion as the square 
of the distance increases. In variable 
forces, theorems similar to those above may 
be exhibited, by using the fluxions of quan- 
tities, and afterwards taking the fluents of 
the given fluxional equations. And herein 
consists one of the great excellencies of the 
Newtonian or modern analysis, by which 
we are enabled to manage and compute the 
effects of all kinds of variable forces, whe- 
ther accelerating or retarding. Thus, using 
the same notation as above for constant 
forces, viz. /, the accelerating force at any 
instant ; f, the time a body has been in mo- 
tion by the action of the variable force ; v, 
the velocity generated in that time ; s, the 
space run over in that time ; and g = 16 ,^ 
feet ; then is s = . — v t ; v 
2g/* 
V 
%gjt,t „ 2g/’“' 2gs 2gt. 
In these four theorems, the force/, though 
variable, is supposed to be constant for the 
indefinitely small time t ; and they are to 
be used in all cases of variable forces, as 
the former ones in constant forces; viz. 
from the circumstances of the problem un- 
der consideration, deduce a general expres- 
sion for the value of the force /, at any in- 
definite time t ; then substitute it in one of 
these theorems, which shall be proper to 
the case in hand ; and the equation thence 
resulting will determine the corresponding 
values of the other quantities in the pro- 
blem. It is also to be observed, that the 
foregoing theorems equally hold good for 
the destruction of motion and velocity, by 
means of retarding or resisting forces, as 
for the generation of the same by means of 
accelerating forces. 
FORCEPS, a pair of nippers, or pinchers, 
for laying hold of and pulling out any 
thing forced into another body. 
Forceps, in surgery, &c. a pair of 
scissars for cutting off, or dividing, the 
fleshy or membraneous parts of the body, 
as occasion requires. 
Forceps are commonly made of steel, 
but those of silver are much neater. 
FORCER, or forcing pump, in mechanics, 
is a kind of pump in which there is a forcer 
or piston without a valve. See Pump. 
Forcible entry and detainer. Forcible 
entry, is a violent actual entry into a house 
or land, & c., or taking a distress of any 
person, armed, whether he offer violence 
or fear of hurt to any there, or furiously 
drive any out of the possession ; if one enter 
another’s house, without his consent, al- 
