MK1 HODS oi-1 CASTINMi TKST li.ARS FOR 'I'll K A. K. A. 55^
too much praise cannot be accorded Dr. Richard Mol-denkc, as chairman, for the great zeal, time, and much money he has expended in supervising1 and assisting in the aee<miplishment of this \vork. We have also to men-tioii as entitled to credit Mr. II. K. Diller and Mr. A. IVehstein, who assisted Dr. Moldeiike in making physical tests and chemical analyses. Credit is also due to the respective persons and firms mentioned in connection with each table of series A to L, for their valuable assistance and kindness in donating* the castings required for the test bars.
The transverse bars were made about 15 inches long and tested i 2 inches between supports. Any depressions that the knives might make in the surfaces of the round or square bars were noted in recording the deilectinn. Two tests were made, on an average, of each kind in all the different sixes of bars. The averages of the two tests in the original, tables of the selected bars are .recorded in Tables 115 to 126, so as to condense the results. The round bars are selected in preference to the square bars in compiling Tables 115 to i j6, for the reason, that they are better than square bars, as is explained in Chapter LX.I.V.
The tensile tests in original tables, all of which were compiled by I >r. R. Moldenke, wc.re reduced to strength per square inch and shown in connection with their actual breaking load, but the author has separated, these so as to give the strength per square inch of the tensile tests in the independent Table 126, to be above the chemical analyses of the different specialties shown in Table 127, both seen on page 570. The actual load at which tensile bars broke is shown in the last column, of easts.A, H, ("and (5 to L. The form of bars as turned for the tensile tests is seen in Fig. i.-pS, page 583.
The bars cast in dry sand and j^reen sand showedast on end, us such will tfive truer results than the [J4™inch round bar in general practice, especially in making comparison <>i; the widest ranges in grades.temper '' or damp- ,| |