Michelson A.A., Morley E. Influence of Motion of the Medium on the velocity of Light. // American Journal of Science, Ser. 3, 1886, vol. 31

The result of this work is therefore that the result announced by Fizeau is essentially correct; and that the luminiferous ether is entirely unaffected by the motion of ike matter which it permeates.

Art. XXXYII.—Note on the Structure of Tempered Steel; by C. Barus and V. Strouhal.

In view of the experiments oh the structure of steel by Dr. Hennig* now in progress in Professor Kohlrausch’s laboratory, we avail ourselves of the permission of the Director of the Geological Survey and of the Editors of this Journal, to insert a brief but typical example of our own results here. The complete paper will appear in Bulletin No. 35 of the Geological Survey, now in the hands of the Public Printer.

The steel cylinder (length 6 cm., diameter 3 cm., weight 332 g.) to which the data refer was quenched glass-hard in the ordinary way. The consecutive cylindrical shells were then removed by galvanic solution, and the necessary measurements made to determine the density of each.

Let A be the density (0° C.) of the consecutive cores. Let R, #, d, be the mean radius, thickness and density, respectively, of the consecutive shells. Then if the nth core be left after the removal of n shells, the table gives the digest in question.

Shell or core No. A.

0 7-8337

0 7*7744

1 7-7734

2 7-7727

3 7*7742

4 7*7734

5 7*7750

6 7*7784

7 7*7813

8 7*7817

, 9 7*7841

10 7-7869

11 7*7894

12 7-7919

13 7-7911

14 7-7937

15 7-7979

16 7*7999

17 7-8017

18 7-8013

19 7-8027

20 7-8009 Warlington-Prague,

*Wied. Ann., xxvii, 351, 1886.

April, 1886.

Remarks. Before quenching. After quenching.

Core perceptibly fileable.