180 
An Essay on the Game of Billiards . 
[June, 
consimility before and after reflection, with which they are endued, and the 
precision their various rays display, together with the facility of making and 
multiplying experiments, seem to have recommended these subjects for examination 
a s paramount to all others in the field of nature, and fittest for the purpose of hav- 
ing the merits of the present question ascertained. But it appears, as if the 
issue, which (fostered by the greatness of a name), is now so much revered, 
and rules with universal sway, had its birth in a confidence-perhaps too firm, 
(though resulting from careful and persevering investigation thus directed,) and 
was thence transferred, rather by analogy than otherwise, to matters not supposed 
as favorably submissive to experiment : yet if the instances already brought 
forward, wherein it has been endeavoured to show this principle cannot hold, 
deserve any notice ; may not the same kind of argument be used to render the 
position at least suspected ; and negative universality made the inference from 
many particulars, with as much propriety, as positive from only one; and 
sti more so, should the validity of this particular instance be at all disturbed, 
by hypotheses not at war with reason, or established principles ? 
It will be admitted, that with regard to light, no variation between the angle of 
accidence and reflection has been observed to take place either through the interven- 
tion of many mirrors, or any distance the eye can comprehend, after repeated trials: 
but it does not follow, that what has not appeared to our limited faculties can have 
no existence : and, if we consider the wonderful minuteness of its particles, compar- 
ed with the smallest division of matter which can be distinctly presented to oar 
senses; as also, that no two points within the same horizon are sufficiently 
distant to give the least idea of its progressive velocity, why may it not be 
projected from the luminous body with rotary motion likewise,' and its momen- 
turn have a similar effect upon the angle of reflection, for aught we can per- 
cen-e to the contrary? But waving this, which seems to lie beyond the read 
of intuition, and though some bodies at least must be allowed to have rotation 
-antecedent to reflection, no small degree of it is acquired after, from the veiy act 
of striking against the reflecting surface ; because the point of aggression being 
X:“ y rT" it - and ‘ he direCtiOD ° f the --dental Une, whatever be 
mns be the “ Z*?* * *° tU ™ “ P™porflon ,0 the interval 
“efrne n, 7^“”' CTe " %I,t> Which is now ‘he subject principally 
.bedilEciht^ 
of stprlmo mfn 7 cen eel opinion should pass as proof 
or sterling rate, or currency be offered for its assay. 
But to return. Players in their noviciate not i-no™- 7 , , , 
of rpflprimn j , iate ’ not ^ n °wmg how much the angle 
or reflection depends upon the manner of striking u u 
bly from that nf amWio S llklD o tbe > when it differs sensi- 
1 It has been found that the fm-ep „•*. , . , , 
ties of matter multiplied by their velo V ™ , ’ 0d,eS move » is > as their quanti- 
se eclipses of Jupiter’s satellites that ' aH Astronomers have proved from 
than a cannon ball at the moment of i! m ° VeS Uvo miIIions of times faster 
would be intolerable to the most stnbk * ^ Ul ' Se ’ lvben tl,e Ieast grain of sand 
*• Panicles, with nl, this vZly A* “» 
organ as the eye. we are left ration-, 1 P ainful impression on so delicate an 
minuteness. means to be assured of their extreme 
