STATE GEOLOGIST. 127 
the floors were tested to 900 pounds per square foot. The general appear- 
ance of the columns was as good as when put in place. The expanded 
metal which was protected by cinder concrete showed a little rust in a few 
places, but not enough to give any apprehension. In fact, they said it ap- 
peared to have ceased rusting long ago. 
Pabst Hotel, New York.—The Pabst Hotel, at the. corner of Broad- 
way and 42nd street, N. Y., was built in 1898 and torn down in 1903. The 
metal enclosed in concrete and terra cotta showed some rust, about as 
much as would occur while the concrete was thoroughly using all the water 
within it. This was a cinder concrete and quite porous. 
World’s Fair Spectmen.—The writer, who was engaged at the 
Exposition Grounds throughout the building and operation of the 
World’s Columbian Exposition at Chicago, saw the construction in 1892 
of the cement exhibit of the Alsen Portland Cement Company. One 
portion of their exhibit was a concrete pedestal upon which were two large 
concrete figures, one of which held aloft a banner bearing the Alsen’s ad- 
vertisement. The writer visited Jackson Park in the summer of 1902 
just as the final destruction of the statue occurred. It had long been 
broken down, but was then being broken into smaller pieces to act as fill- 
ing along the embankment of a lakelet. While breaking up the head of 
this figure, a screw used as a holding pin by the artist who made the statue 
was brought to view. It was in excellent condition; a large portion of 
the surface came out of the concrete as bright and untarnished as the 
day it went in. A small part of the threaded portion which had not been 
intimately in contact with the cement showed a coating of rust; about as 
much as would have occurred if the screw had been wet and lain exposed 
for two or three days. This screw had been in service ten years, and for 
several years the head of the figure in which the screw was imbedded had 
been lying in the marshy sand at the south end of Jackson Park. A longer 
test would not have proven more conclusively that dense concrete pro- 
tects steel against corrosion. 
Norton’s Experitments.—Prof. C. H. Norton, engineer of the Insur- 
ance Engineering Experiment Station, Boston, made a series of tests with | 
steel and iron imbedded in cement, concrete and cinder concrete to deter- 
mine the effect of the different classes of concrete upon the metals as to 
danger of rusting. Two brands of cement were used—neat, and with sand, 
stone and cinders. Concrete bricks 3 inches by 3 inches by 8 inches in di- 
mensions with three specimens of steel in each, a rod of mild steel 6 inches 
long and % inch diameter, a bar of soft sheet steel 6 inches by I inch by 
I-32 inch, and a strip of expanded metal 6 inches by I inch in size re- 
spectively were used in each brick. He subjected these bricks to different 
conditions as follows: Some were subjected to steam, air and carbonic 
acid, some to air and steam, some to air and carbonic acid and one-fourth 
