106 The Philippine Journal of Science 1921 
the district engineers directly in charge of Bureau of Public 
Works building projects throughout the Philippines. A few of 
the field test specimens represent concrete that has entered into 
the construction of some of Manila’s modern business edifices, 
such as the Manila Hotel, the Masonic Temple, and the Chaco 
Building. An interesting series of results was secured from 
test specimens cast in the field during the construction of the 
United States Army pier in Manila.2 These results are espe- 
cially noteworthy in that they show that the careful selection 
of aggregates, a close supervision of all mixing operations, in- 
cluding the proportioning of the cement, sand, water, gravel, 
and crushed stone, together with conscientious inspection of 
the process of putting the concrete in place, so as to compel 
sufficient spading and tamping of the mix, will under field con- 
ditions yield a concrete that is as strong as concrete made from 
the same materials in the laboratory. . 
The number of tests recorded totals 1,677. In Table 1 is 
shown the number of concrete specimens, classified according 
to provinces that submitted aggregates or test pieces. This 
table will give some idea of the amount of constructional ac- 
tivity carried on by the Government, throughout the Philip- 
pines, during the past decade. 
Preliminary to the erection of concrete structures built under 
the supervision of the Bureau of Public Works, it has been cus- 
tomary to send to the Bureau of Science, for testing, samples 
of sand and gravel occurring as near as possible to the building 
site, and at the time thought by the engineer to be the best 
available material for the work contemplated. The samples 
of aggregates arrived at the materials testing laboratory 
packed in gunny sacks, cartons, wooden boxes, kerosene cans, 
and cement barrels, and ranged in quantity from barely suf- 
ficient to make six briquettes and one or two 6-inch cubes, to 
a barrelful (about 3.8 cubic feet) each of sand and gravel or 
crushed stone. In general it may be said that the samples were 
too small, and whether they were truly representative of the 
deposits or not is problematical. In several instances, tests 
*For these specimens I am indebted to Mr. George H. Bevin, C. E., 
general superintendent of construction, Quartermaster Department, United 
States Army, who turned over to the Bureau of Science one hundred 
seventy-two 6-inch concrete cubes that were taken from batches used in 
making the piles, braces, and floor of the Quartermaster’s pier. Fourteen 
cubes were tested and the cubes remaining are being preserved for long- 
time tests, a portion under the eaves of the laboratory roof, and the other 
portion in a steel cage submerged in the salt water beneath the pier. 
