HOROLOGY. 
337 
l\o. of f a // or aclintr Diameter of the Pinion. 
Teeth. ° J 
4 — two full teeth of the wheel, unrounded, and the 
fpace between. 
5 = three teeth, rounded from point to point, 
6 — three full teeth, unrounded. 
7 three full teeth and a quarter of a fpace beyond. 
8 = four teeth, rounded from point to point. 
9 = fomewhat lefs than four full teeth. 
10 ~ four full teeth. 
11 = no meafure given. 
it.—, five full teeth. 
13 — no meafure given. 
14 — fix teeth, rounded from point to point. 
15 = fix full teeth. 
The pinions in watches, he remarks, muff be fmaller 
in companion with their wheels than in clocks, agreea¬ 
bly to what we have above laid. 
Having recommended the plan of dividing the whole 
movement of tire going-part into three portions, (any one 
of which may be altered at pleafure, without affecting the 
other two,) we mall here introduce three feparate Tables 
of the different portions, with a view of giving a great 
irariety of trains, and of thus hiving ciock-inakers the 
trouble of tedious calculations. 
I. Firjl Portion of a Clock-movement. 
Hours. 
6 
7 1 
8 
9 
IO 
I I 
12 
13 
14 
’5 
l6 
3 
18 
2 I j 
24 - 
27 
30 
33 
36 
39 
42 
45 
48 
4 
24 
28 
32 
36 
40 
44 
48 
52 
56 
60 
64 
S 
30' 
35 
40 
45 
5 ° 
55 
60 
6 5 
70 
75 
8g 
6 
36 
42 
48 
54 
60 
66 
72 
78 
84 
90 
96 
7 
42 
49 
5 6 
63 
70 
77 
84 
9 1 
98 
I0 5 
112 
8 
48 
56 
64 
72 
80 
88 
96 
IO4 
I 12 
120 
128 
9 
54 
63 
72 
81 
90 
99 
108 
117 
J 26 
*35 
144 
IO 
60 
70 
80 
90 
IOO 
f IO 
120 
I 30 
I40 
150 
160 
II 
66 
77 
88 
99 
HO 
I 2 I 
I 32 
i 43 
1 54 
165 
1 76 
I 2 
7 * 
84 
96 
IOS 
120 
I 32 
144 
156 
168 
180 
192 
13 
78 
9 i 
I 04 
117 
I 3c 
143 
i 5 6 
IS. 
182 
T 95 
208 
14 
84 
98 
112 
126 
140 
1 54 
168 
182 
196 
210 
224 
15 
90 
i* 05 
120 
'35 
15c 
i6 5 
1 Sc 
I95|2IO 
225 
24a 
16 
I f3 
L OS 
128 
144 
160 
176 
192 
2081234 
240 
256 
II. Second Portion of a Clock-movement. 
Factors. 
6 ] 
7 . 
8 
9 
IO 
11 
I 2 
13 
*4 | 
151 
l 6 
+ 1 
24 
20 
32 
36 
40 
45 - 
"48 
52 
56 
60! 
64 
45 I 
90 
105 
I 20 
1 35 
1 5 ° 
1 65 
180 
*95 
210 
22 5 
240 
47 \ 
30 
60 
I 
14 J 
84 
98 
I 12 
126 
140 
1 54 
168 
182 
196 
2 I0: 
244 
42 \ 
27 
36 
45 
54 
1 co 
r 
I 
72 
! 3 l J 
SO 
120 
160 
200 | 
. 4 xV \ 
60 
I 
13 J 
78 
9 1 
IO4 
it 7 
130 
i 43 
169 
182 
1 9 5 1 
208 
5 \ 
30 
3 5 
40 
45 
5 ° 
55 
60 
•65 
70 
75 ! 
80 
12 ) 
72 
84 
96 
108 
I 20 
I 32 
144 
156 
168 
180)192 
5 ir] 
6c 
** 1 
66 
77 
88 
• 99 
no 
121 
132 
143 
1 54 
i6 5 
176 
6 1 
36 
42 
48 
54 
60 
66 
72 
78 
84 
90 
96 
10 J 
60 
70 
80 
90 
100 
110 
120 
I 30 
140 
150 
160 
, 4 ° 
60 
80 
IOO 
9 J 
54 
63 
72 
81 
90 
99 
108 
117 
126 
135 
144 
7 1 
,42 
49 
5 6 
63 
70 
77 
84 
9 1 
98 
io 5 
I T2 
8 f J 
60 
120 
77 1 
60 
75 
80 
105 
I 2 C 
8 J 
48 
56 
64 
72 
80 
88 
96 
104 
112 
120 
128 
III. Third Portion of a Clock-movement. 
5 
7 
8 j 
9 
10 
11 
12 
11 
*4 
! 5 
^ Cu 
12 
3 ° 
35 
L C 
i -5 
50 
55 
6 c 
6 c 
70 
75 
2 
9-80 
15 
] 
32 
3 fi 
40 
44 
48 
52 
56 
6 c 
2C 
V b 
21 
24 
27 
30 
33 
36 
35 
. 4-2 
45 
3c 
I 2 
T 4 
I 
18 
20 
22 
24 
26 
2? 
30 
l 2 
5 r - 
75 
~2 
6’27 
15 
1C 
35 
*r w 
rS 
50 
55 
60 
65 
70 
75 
z 5 
I 3 
2 I 
2 4 
30 
33 
3 6 
35 
4 - 2 . 
45 
3.9 
'1 5 
20 
2'5 
30 
■35 
1 5 
36 
42 
4- 
54 
60 
66 
72 
78 
84 
90 
3 
4‘3 5 
18 
3° 
35 
4c 
-:-5 
5 ° 
55 
60 
65 
70 
75 
3 c 
18 
2 I 
24 
27 
3 ° 
3 3 
36 
39 
42 
45 
45 
12 
14 
16 
20 
22 
24 
26 
28 
30 
15 
42 
49 
'56 
53 
.70 
77 
84 
■ 9 1 
98 
10 5 
1 
$ 2 
3-20 
25 
>° 
35 
40 
V 5 
5 ° 
55 
6c 
65 
70 
75 
3 5 
£•8 
21 
24 
30 
33 
36 
39 
42 
45 
I ; 
48 
5 (: 
64 
/ 
80 
Is 
96 
IO4 
I I 2 
I 20 
4 
2 ‘45 
20 
4 2 
48 
54 
60 
66 
72 
78 
84 
90 
24 
35 
4 C 
44 
5 ° 
55 
60 
6 5 
70 
75 
30 
24 
28 
32 
36 
40 
44 
4 -o 
52 
S§ 
6c 
4 - 
if 
: 1 
24 
2 7 
30 
33 
36 
39 
42 
45 
13 
■54 
H 
72 
81 
90 
99 
108 
117 
126 
135 
1 '9 3 5 
27 
3 C 
3*5 
4 C 
4-5 
5 ° 
55 
6 c 
65 
70 
75 
45 
18 
: 1 
24 
7 
30 
33 
36 
39 
42 
45 
1 f 
Sc 
70 
80 
90 
IOO 
I IO 
120 
130 
14-c 
150 
5 
*'57 
25 
3 e 
42 
48 
54 
6c 
66 
72 
78 
84 
90 
30 
3 C 
35 4 ° 
45 
5° 
55 
60 
6 5 
70 
75 
5° 
18 
21U4 
27 
30 
3 3 
36 
39 
42 
45 
Explanation .—Table I. contains numbers fuitable for the 
great wheel, and the pinion on the arbor of the centre- 
wheel, together denominated the firf portion of a clock- 
movement, which is that on. which the duration of mo¬ 
tion at one winding-up depends; the numbers on the up- 
permoft horizontal column, from 6 to 16 inclnfively, re-, 
prefent fo many pinions; the numbers in the firft vertical 
column, from 3 to 16 inclufively, are the refpeftive hours 
in which the barrel or fufee turns once, as the cafe may 
be ; and the larger numbers, beginning with 18 and end¬ 
ing with 256, in the interfeftions of the horizontal and 
vertical columns, are the great wheels. By way of exem¬ 
plification, fuppofe we want a fufee to revolve in twelve 
hours, with a pinion of 8 on the arbor of the centre- 
wheel, the interfeclion of 12 hours at the left-hand fide, 
and tight at the top, gives 96 for the number of teeth in 
the great wheel, to produce the deiired effect; or if the 
pinion had been required for a wheel of 96, to revolve in 
12 hours, over 96, in the column of 12 hours, hands the 
pinion 8. In the fame manner for 4 hours, and a wheel 
of 48, the pinion will be 12, and vice verj'd. 
Table II. contains wheels and pinions fuitable for the 
fecond portion of a clock-movement, or firft portion of the train, 
being that which effefts a multiplication of 60, and regu¬ 
lates the velocity of the feconds-hand, by making its ar¬ 
bor revolve in one minute. This might be done by one 
large wheel of 300, and a fmall pinion of 5; but fuch a 
conftruftion would require a large frame ; a compofition. 
of two wheels and two pinions is therefore fubftituted to' 
produce the fame effect more conveniently, the firft wheel 
being placed on the centre or hour arbor that carries the 
minutes-hand, and the laft pinion on the arbor of the 
feconds-hand that revolves in a minute. The upper- 
moft horizontal column contains the pinions from 6 to 16 
inclufive, like Table I. and the left-hand vertical column 
contains couplets of rafters, which, multiplied together, 
produce 60 always as a produft. Any pair of faftors, 
which are coupled together by a ^ , may be taken at plea¬ 
fure, and the wheels in the fpace-s. made by the interfec- 
4 R tions 
VOL. X. No. 665. 
