NUMBERS. 
75)394-87999(5 Hours. 
375 
19:87999 
[) 
73) 1192.79999(15 Minutes. 
75 
442 
375 
67-79999 
60 
75)4067.99999( 54.24 Seconds. 
375 
2g 
30° 
Hen nce it appears, rs, that xyths of 365.2422 days is equal 
to 2 
4 Tee may be fometimes abridged, by con- 
ver ting the vulgar fraétions into a ‘decimal, where there is no 
rena ew then by multiplying thereby, inftead of di- 
viding ; t 
75)6 ool. 08 365.24222 
08 
29.2193777 Days. 
24 
8775111 
43875555 
5.2650666 Hours. 
60 
15.9040000 Minutes. 
60. 
54.2400000 Seconds. 
Either of thefe methods may be ufed with a like re- 
inftead of the wheel, we make the pinion the driver, 
r denominator of the fraction, the motion of the fecond 
.24222 days is 
equal to 4565 12" 36™. 
tions, when the parts of the fraCtion are reverfed, points out 
of attending very accurately to the circum- 
the neceffit 
he driver being made the denominator of the 
flance of t 
Sracion 
The revolutions of the primary planets in the common 
Lagi va there is only one pair of wheels to each 
are eftimated by this cafe 
Lappe that one of the pair is immoveably fixed, 
and the thee put in motien by being carried round it, w 
their teeth are conneéted, the fixed wheel is the caufe of 
motion, and is therefore to be called the driver. 
42 
But the velocity, or mea/fure of motion, in any particular 
wheel, is not the only effe& that is to be attended to in 
phe aoe oe the diredion of motion is alfo to be 
obferved, 
whether the horizontal siheci be ie above or below the 
oO one 
—When a fi imple motion is produced by a train of 
wheels and aes , the ratio of veloc 
6 
“ driving a third pinion of 7; then the operation abridged 
will ftand thus : y 6 ee 7 336 
40 56 94080 
appears that the number of revolutions gained is 280, which - 
= 280; whence it 
would have been fo many lo Pinions been the 
drivers. By this general rule the trains of all the planets in 
orreries may be co however lex, provided the 
Supporters of the wheelwork be fixed in a ftationary pofition. 
After a train is reduced to a fimple fra¢tion, the time cor- 
in a tropical year, the laft pinion of 7 will be carried round 
J of 365.24222 days, which time isequal to 1¢ 7! 
e in the fame 
Caf @ 3— 
of a worm or ondlefs 
ture of the —- ane be carefully examined ; é 
i e be on thre whether the inclination 
