The results of crushing tests of brick vary greatly, depending on the details of the tests made. Many reports fail to give the details under which these tests are made, and in that case the real value of the results of the test as announced is greatly reduced.

The following results were obtained at the U. S. Arsenal at Watertown, Mass., by F. E. Kidder. The specimens were rubbed on a revolving bed until the top and bottom faces were perfectly true and parallel.

Make of Brick

No. of Specimens Tested

Pressure at which Specimens

Began to Fail

Compression (per sq. in.)

Philadelphia Face Brick

3

3,527

lbs.

5,918

lbs.

Cambridge Brick

4

4,655

,,

12, 186

,,

Boston Brick

3

7,880

,,

11,670

,,

New England Pressed

4

4,764

,,

12, 490

,,

The following results were obtained by C. Y. Davis, the tests being made at the Watertown Arsenal:

Kind of Brick

Compression (per sq. in.)

Kind of Brick

Compression (per sq.in.)

Kind of Brick

Compression (per sq. in.)

Red

9,540

lbs.

Pressed

6,470

lbs.

Arch

7,600

lbs.

,,

*8,530

,,

,,

*9,190

,,

,,

*10,290

,,

,,

6,050

,,

,,

5,960

,,

,,

6,800

,,

,,

6,700

,,

,,

6,750

,,

These specimens were tested to select brick for the U. S. Pension Office at Washington, D. C. The specimens tested were submitted by manufacturers. * Indicates the brick selected.