24 THE RUMFORD FUND 



JACQUES, WILLIAM W. Light transmitted by one or more Plates 



of Glass, x, 389. 1875. 

 GIBBS, WOLCOTT. Optical Notices. 1. On a New Optical Constant. 



2. On a Method of Measuring Refractive Indices without the 



Use of Divided Instruments, x, 401. 1875. 

 WILLIAMS, CHARLES H. Intensity of Twilight, x, 421. 1875. 

 CROSBY, WILLIAM O. Light of the Sky, x, 425. 1875. 

 PICKERING, EDWARD C., and STRANGE, D ALSTON P. Light absorbed 



by the Atmosphere of the Sun, x, 428. 1875. 

 PICKERING, EDWARD C., and STRANGE, DALSTON P. Tests of a Mag- 

 neto-Electric Machine, x, 432. 1875. 

 AMORY, ROBERT. On Photographs of the Solar Spectrum, xi, 70. 



1875. 

 TROWBRIDGE, JOHN. On the Effect of Thin Plates of Iron used as 



Armatures to Electro-Magnets, xi, 202. 1876. 

 TROWBRIDGE, JOHN. On the so-called Etheric Force, xi, 206. 1876. 

 TROWBRIDGE, JOHN. On a new Form of Mirror Galvanometer, xi, 



208. 1876. 

 PEIRCE, BENJAMIN O., JR. On the Induction Spark produced in 



Breaking a Galvanic Circuit between the Poles of a Magnet, xi, 



218. 1875. 

 WILSON, WILLIAM P. Condensers and Geisslers Tubes, xi, 282. 



1875. 

 PICKERING, EDWARD C. Comparison of Prismatic and Diffraction 



Spectra, xi, 273. 1875. 

 AMORY, ROBERT. On Photographs of the Solar Spectrum, xi, 279. 



1876. 

 HOLM AN, SILAS W. On the Effect of Temperature on the Viscosity 



of Air, xii, 41. 1876. 

 PEIRCE, BENJAMIN O., JR. Note on the Determination of the Law 



of Propagation of Heat in the Interior of a Solid Body, xii, 143. 



1877. 

 HARKNESS, WILLIAM. Theory of the Horizontal Photoheliograph 



including its Application to the Determination of the Solar 



Parallax by Means of the Transits of Venus, xii, 186. 1877. 



