Chap. II.
COMPOSITION AND USE OF MINERALS.
691
sure; divide the pressure or weight in pounds by 15,000, and the quotient will be the areaof the section of the block in inches.
For story posts of warehouses or other buildings, the following table was calculated bvMr. Tredgold.
A Table showing the Height that mag be placed with Safety on Cast-iron cylindrical Columnsfrom 1 to 12 Inches Diameter.
Length orHeight.
2 Feet.
4 Feet
6 Feet.
8 FeetJlOFeet.
12 Feet.
14 Feet.|l6Feet.
18 Feet.
20 Feet
22 Feet
24 Feet.
Diameterin Inches
Cwt.
Cwt.
Cwt.
Cwt.
i
i cwt.
Cwt.
Cwt.
Cwt.
Cwt.
Cwt.
Cwt.
Cwt.
1
18
12
8
5
■ 3
2
o
1
1
1
M
44
36
28
19
! 16
12
9
7
6
5
4
3
2
82
72
60
49
40
32
26
22
18
15
13
11
129
119
105
91
77
65
55
47
40
34
28
25
3
188
178
163
145
128
111
97
84
73
64
56
49 |
257
247
232
214
. 191
172
15G
135
119
106
94
83 |
4
337
326
310
288
i 2GG
242
220
198
178
160
144
130 !
*1 .
429
418
400
379
I 354
327
301
275
251
229
208
189 '
5
530
522
501
479
, 452
427
394
365
337
310
285
262 j
6
616
607
592
573
j 550
525
497
469
440
413
386
360 !
7
1040
1032
1013
989
i 959
924
887
848
808
765
725
686
8
1344
1333
1315
1289
! 1259
1224
1185
1142
1097
1052
1005
959 !
9
1727
1716
1G97
1672
; 1640
1603
1561
1515
1467
1416
1364
1311 !
10
2133
2122
2130
2077
! 2045
2007
1964
1916
1865
1811
1755
1697 j
11
2580
2570
2550
2520
! 2490
2450
2410
2380
2230
2250
2190
2130 1
12
3071
3050
3040
3020
2970 ; 2930
2900
2830
2780
2730
2670
2600 ;
A Table showing the Depths of square Beams or Bars of Cast-iron of different lengths, tosustain Weights (its own being included ) of from 1 to 500 Tons when supported at theEnds and loaded in the Middle ; the Deflection not to exceed one-fortieth part of an Inchfor each Foot in Length.
Tons.
4
G
1 8
10
12
14
16
18
20
22
24
26
28
30
32
I 3-1
36
38
40
1
25
3*0
3*5
39
4-3
4*6
4-9
5-2
5-5
6-8
6-0
6-3
6-5
67
7-0! 7*2
7*4
7-5
7-8
2
21
3 5
41
47
51
55
5£
6*2
6-5
67
7-2
7-6
77
87
8-3 8-5
87
9-0
9-2
3
3 i
4'0] 4 6
5-1
57
61
6-5
6-i
77
7-6
77
87
8-6
87
9-2
9-4
97
100
101
4
3-5
4-3; 4-S
55
GC
6*5
7(
7-4
77
8-2
8-5
87
9-2
9-5
97
10-1
10-4
107
no
5
_
4-5
5*2
5-fi
6-4
6-9
7-4
7-1
8-2
8-6
tn
9-4
97
10-1
10-4
10-7
11-0
11*2
11-6
6
_ .
_
5 5
61
67
7-2
77
8-2
8-6
9-C
9-4
97
10-2
10-5
107
11-2
11-5
11-9
121
7
_
_
57
67
6*9
7-5
8-C
8-5
87
9-4
97
10-2
10-6
11-C
117
11-7
12-0
12-3
12-7
8
_
_
5*£
6-6
7*2
7-8
87
8-8
97
9-7
10-1
10-6
10-9
11-3 11*7
12-0
12-4
12-8
131
9
_
_
6-C
6-8
7-4
8-0
8*5
9-C
9-5
IOC
10-4
107
117
117 127
12-4
12-8
131
13-5
10
_
_
_
6*9
7-6
8*2
8-8
97
9-8
io-a
107
11-2
J 1*6
127
12-4
12-8
131
13-5
13*8
11
—
_
_
7*1
7-8
84
9C
9-5
10-C
10-5
117
11-5
117
127
12-7
137
135
13-8
14-2
12
_
_
_
7*2
7-9
8-6
9-2
97
10*2
10*8
11-2
11-7
12-1
12*5
137
13*4
137
141
14-5
13
_
_
_
74
81
8-8
9*4
y-'j
10-4
110
J17
11 -'J
12-4
12-8
13-2
136
14*0
14-4
147
14
_
_
_
7-5
8-3
8-9
9-5
10-1
10-6 H I
117
12-1
12-6
137
13-4
13-8
14-2
11-6
15-0
15
_
_
_
77
8-4
9-1
9 7
107
107
11-4
11-9
12-3
12-8
13-2
13-7
14-1
14-5
14-9
15-3
16
_
_
_
7'8
8-5
9*2
9-8
10-4
11-C
11*5
120 12-5! 13-0
13-5
137
14*3
J47
151
15-5
17
_
_
_
7*9
87
9-4
106
10-6
11-2
117
12-2
12-7i 13-2
137
14-1
14*5
147
15-4
15-8
18
_
—
_
8*0
8-8
9-5
101
10*8! 11*3
11-9
12-4
12-9
13 4
137
14-3
147
16*1
15-6
16-0
19
_
_
_
8-1
8*9
9-6
10-3
10*9
11-5; 120
120
13*1
13-6
14-1
14*5
15*0
15-4
15-8
16-2
20
__
_
_
_
9*0
97
10-4
11-0
11*6
12-2
127
13-2
13-8
14-2
14-7
15-1
15-6
16-0
16-4
30
_
_
_
_
_
108
11-5
I2-2| 12-9; 13-5
14-1
14*7
15-2
15-7
16-3
16*8
17-3
177
18-2
40
12-4
]3*11 13-8 14*5
16-1
157! 16-4
16-9
17-5
18-0
18-5
197
19-5
60
_
_
_
_
_
_
_
13-9
14-6! 15-3
160
16-6; 17-3
17*9
18-5
19-0
19-6
201
207
60
_
_
_
_
_
14-5! 15-3' 160
167: 17-4
18-1
18-7
19-3
19-9
20-5
21-1
21-6
70
_
_
_
_
_
_
_
15 1
15-9 167
17-4
18-2
18-8
19*5
20-1
20-8
213
22-0
22-5
80
—
17‘2
18-0
187
19-4
201
20-7
21-4
22-0
22-6
232
90
_
_
_
_
_
_
_
_
_
17*8
18-6
19-3! 20-0
20-7
21*4
22*1
227
23-3
23-9
100
_
_
_
_
_
_
_
_
_
_
19-0
19-8! 20-6
21 -3
22*0
22-6
233
23-9
24-5
no
20-3 21-0
21 -8
22-5
23-2
23-8
24-5
25-1
120
_
i—
_
_
_
_
—
_
_
_
20-8
21-5
22*3
237
237
24-4
25-0
25 7
130
_
_
_
_
_
_
_
_
_
_
_
_
220
22-7!23-5
24-2
247
25-5
26-3
140
_
_
_
_
_
_
_
_
_
_
_
_
_
23-2! 23-9
24*6
25 4
260
267
150
_
_
_
_
_
_
_
_
_
_
_
_
_
23-6
24-3
25-0
25-8
26-5
27-2
200
_
_
_
_
_
_
_
_
_
_
_
26-2
27-0
277
28-5
29-2
250
27-6
28-5
29-4
30-1
310
300
28-9
29*9
307
31 -5
32-0
360
_
_
_
_
_
_
_
_
_
_
—
_
_
_
30-0
31-0
320
33-0
33-7
400
31-1
32-0
327
33 9
34-7
450
—
_
_
_
_
_
_
_
_
_
_
_
32 0 33-1
340
34-8
3.VR
500
-
33-8
34-8
357
367
Deflectionin Inches.
■1
•15
•2
•25
•3
•35
•4
*45
■5
•55
•6
•65
7
75
-
8*5
■9
•95
1-0
V V