IO8 TOWERS AND TANKS FOR WATER-WORKS. 



been determined as applicable to steel columns less than 90 

 radii. 



To use the table, divide the length of the column in feet by 

 the least radius of gyration of the section, and from the corre- 

 sponding ratio of the table find the unit strength of the material 

 in pounds, which, multiplied by the combined area of the shape, 

 will give the safe load in pounds for a column of the required 

 length and cross-section. 



Of late numerous straight-line compression formulas have 

 been presented, and diagrams constructed from same have sprung 

 into common use. Herewith is reproduced one prepared by 

 Mr. O. W. Childs, C.E., and published in January, 1900, by the 

 Engineering News* 



