THAT BIG DESTRUCTOR CHIMNEY.

Dominion, Volume 1, Issue 148, 17 March 1908, Page 4

THAT BIG DESTRUCTOR CHIMNEY.

Sir,—ln reading" your report of the. abovo this morning, I notico that 240 cubic yards of gravel' and 300 "barrels (or casks) of cemont'.liayo been 'used in its / construction. For trade use, ; architects, builders, ; otc., allow four cubic feet of cement to the barrel. Now for #,little sehool boy work. The aggregate .of four ofgravel and one of cement, when properly mixed and- wetted ready for use, is about the same in bulk as tth'e Eravel when in its dry stato, takes ' the coment to fill' up the interspaces, in tho gravel; otherwise tno aggregate is jnot solid, and honoycombed concrete is .weak. Two' hundr<s and forty cubic yards of gravel yto 6480 cubic ,fect; divide that by 1G (4 and 1), give. 405 barrels :of cement needed to woTk up 240 yards of gravel. If tho gravel is very' small;; and 170 allow' 2ft. extra in bulk for. tho is,; 13ft—you will then require 300 barrels of coment to use up 240 yards, of gravel. Take tho layman that knows nothing about tho business: ho would naturally lmlip tho gravel and; cement'together, 16 gravel and 4 cement,, equal to 20ft. (which is impossible to got)"-;--then he would rcquhre 324, barrels ~ touse .up. 240 yards of. gravel.....Clearly..^there 1 is a' .shortage; of oement usod—that. is, if your report is correct.—l am, etc.,

A.li. (who has been 51 years in the . business). , Potono, March 2. ; . / . • (On tracing our information to its source, wo learn that the' quantities mentioned in .the. article were, intended to. :be .taken as meroly approximate. If tho exact figures were ...available, our . correspondent's criticism iw.ould probably.be found not to apply.)