Proceedings of Scientific Societies. 
Exhibition of a new Spectroscope Slit.— 3 min. — By Romyn Hitch- 
Exhibition of a Thermometer Avith constant Zero Point— 3 min.— 
By Romyn Hitchcock. 
The Measurement of Magnification in the Microscope. — 15 min. — 
By W. Le Conte Stephens. 
Concerning Thermometers.— 20 min.— By Wm. A. Rogers and R. S. 
Woodward. 
Experimental Proof of Newton's Law of Cooling.— 8 min. — By 
Wm. A. Rogers. 
On the Partition of the Mean Kinetic Energy of a perfect gas 
between the rotary and translatory motions of its molecules. — 8 min. 
—By H. T. Eddy. 
Note on the Magnetic Rotation of Polarized Light according to the 
Electro-magnetic Theory.— 10 min.— By H. T. Eddy. 
Researches on Sonorus Sand in the Peninsula of Sinai (with lan- 
tern views).— By H. Carrington Bolton. 
Relative Merits of Dynamometric and Magnetic Methods of Obtain- 
ing Absolute Measurements of Electric Currents.— 30 min.— by Thos. 
Gray. 
A Quadrant Electrometer. — 5 min.— By Harris J. Ryan. 
Magnetic Leakage in Dynamos. — 10 min.— by H. S. Carhart. 
An Improved Standard Clark Cell with Low Temperature Co-effi- 
cient.— 15 min.— By H. S. Carhart. 
On Globular Lightning.— By T. C. Mendenhall. 
A Preliminary Report on the Influence of Temperature upon the 
Color of Pigments. — 15 min.— By Edward L. Nichols and B. W. 
Snow. 
The Solar Condition upon which the Aurora Depends.— 5 min.— By 
M. A. Veeder. 
The Determination of the Amount of Rainfall.— 12 min.— By 
Cleveland Abbe. 
The Hydro-Electric Effect of Stretching Metals.— 15 min.— By Carl 
Barus. 
Additional Experimental Proof of the Constancy of the Relative 
Co-efficients of Expansion between Jessop's Steel and Bronze, between 
the limits of minus 5° and 95° Fahr.— 5 min.— By Wm. A. Rogers. 
Experiments in Duplex Telephony in 1883.— 5 min.— By A. M. 
Roseburgh. 
