On the Strength of Cylindrical Steam Boilers. 
73 
: ickness of plate iro 
which will bear 55, 000 Correuaang tenaci-|Tenacity required 
the square inch ty of each inch wide paren rangi a bat 
veagland to re! ring i nd requir- inch wide, 
strain in the direction! ed to support a press- Sasaie the (itn 
Diameter of] of the curve = ure of 750 Ibs. to the} tending to burst out 
| the boiler | pressure of 750 square inch, calcu-| the head, 
in inches. | the square inch, Peal lated on the formula} on the formula T= 
: : culat y the formu- el af 
laps 25° 2° 4 
inches. Inch. Pounds, Pounds 
meres -0068 375 187.5 
2 -0136 750 375 
3 - 0204 1125 562.5 
4 0272 1500 750 
ae .0341 1875 937.5 
6 -0409 2250 1125 
7 .0476 2625 1312.5 
8 0545 3000 1500 
9 -0613 3375 1687.5 
10 .0681 ee ~_ 3750 1875 
11 0745 —_ 4125 2062.5 
12 0818 4500 2250 
14 + 0954 5250 2625 
16. 1090 6000 3000 
18-4 1227 6750 3375 
a SS 1363 7500 3750 
=. .1490 8250 4125 
24. 1636 9000 4500 
26 1773 9750 4875 
28 1909 10500 5250 
30 .2045 11250 5625 
32 2182 12000 6000 
34 .2318 12750 6375 
36 245 13500 6750 
38 2591 14250 7125 
40° 2727 15000 7500 
42 .2860 15750 7875 
44 .2980 16500 8250 
46 3116 17250 8625 
48 3252 18000 9000 
50 .3388 18750 9375 
13. I am not aware that this subject has been previously treated 
in a general manner, at least as it regards several of the points above 
presented. Mr. Oliver Evans made some particular calculations of 
the strength requisite to sustain the pressure in a boiler of known di- 
mensions, under a tension of wae pe to the square inch. In the 
Vou. XXIII.—No. 1 
