. Electric railway journal . and that of thecolumns is measured by means of base-metal thermo-couples attached to the metal of the columns at fourelevations. An automatic potentiometer recorder is con-nected so that graphic records of temperature can beobtained. The compression and expansion are measured bymeans of wire attached to the column at each end of agage length of 37 in. Readings of vertical movementsare taken by means of microscopes mounted in microm-eter slides. The tests are continued to a breakdown ofthe sample, and hence no inferences as to the compara-tive merits of the differen
. Electric railway journal . and that of thecolumns is measured by means of base-metal thermo-couples attached to the metal of the columns at fourelevations. An automatic potentiometer recorder is con-nected so that graphic records of temperature can beobtained. The compression and expansion are measured bymeans of wire attached to the column at each end of agage length of 37 in. Readings of vertical movementsare taken by means of microscopes mounted in microm-eter slides. The tests are continued to a breakdown ofthe sample, and hence no inferences as to the compara-tive merits of the different column designs shown in theaccompanying illustration can be drawn. The time toobtain failure for the columns tested thus far variesfrom seventeen minutes for the unprotected columns tomore than eight hours for those heavily protected. Dif-ferences of 100 per cent in effectiveness of fire-resistivematerials have already been found between concrete ofdifferent aggregates. The figure below shows severalcolumns after TEST SPECIMENS OF BUILDING COLUMNS BROKEN DOWN IN FIRE TESTS TO DETERMINE EFFECTIVENESS OF COVERINGS January 26, 1918 Electric Railway Journal 195 Cost Data on Special Work Construction—II By M. BERNARD Assistant Engineer Way & Structures Department,Brooklyn (N. Y.) Rapid Transit System This is the second plate of the series of Cost Data on Special Work Con-struction supplementing the series of plates giving Cost Data on Special WorkRenewals. The following four units are of the same types as those coveredin the issues of Dec. 8, page 1043, Figs. 28, 29 and 30; Nov. 10, page 871, Fig. 21. Fig. 5— Side Turnout Length—120 ft. single trackNew construction—7-in. girder rail*—5-in. granite on concreteOld construction—street graded, unpaved
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