XV111 PREFACE TO FIFTH EDITION.
and that the general adoption of correct methods for testing* cast iron is to be retarded by the advocacy of such an unreliable and impractical test bar as the J^-inch square.
The author would not have embodied these remarks in a preface, did he not feel that events warranted them and he trusts it may be the means of doing some good in assisting to abolish an impractical and injurious practice.
THOS. D. WEST.
SHARPSVJLLE, PA., February, 1902.s 574 to c;,S.j. of this work, and also still persist, in advocating the use of '-j-ineh s<maiv bars with the evidence obtainable to prove their militm.-ss for testing cast iron, (iood evidence of the unfit ness of l-..-iiu.'h square bars is ]>resented by Mr. Krep in his book, k* Cast Iron," pa^'cs 173 and 174. Here we find that a slight difference in the fluidity of the same metal ^ave a difference of a hundred pounds in the- body of two '/-inch square bars a quality «*:-.;u'tly in keeping with the evidence presented in this work showing how casilv such small bars are made unreliable by slight variations in. the temper "i" dampness of molding sand and temperature of ponriu;; im'tab