CONTENTS. VU 



PAdE 



M. I. PUPIN. 



A New Form of Vacuum Tube, and a New Electrodynamic Current 



Interrupter 44 



Vacuum Discharges and their Bearing on the Electrical Theory of the 



Solar Corona 72 



Further Experiments in Connection with Vacuum Discharges 124 



A. L. RAWSON. 



The Ancient Inscription on a Wall at Chatata, Tennessee 26 



J. K. HEES. 



Changes on the Lunar Surface 42 



Ancient Astronomical Instruments 106 



Report of Observations on the Comet of 1892 (Swift) made at the 



Columbia College Observatory 120 



HEINRICH RIES 



The Clays of the Hudson River Valley 33 



JOHN TATLOCK, JR. 



Remarks on the Aurora of February 13, 1892 105 



C. H. TYLER TOWNSEND. 



Catalogue of the Described South America Species of the Calyptrate 

 Muscidae 131 



W. p. TROWBRIDGE. 



The Mandibles of the Hudsonian Godwit 30 



H. T. VULTE. 



Commercial Oil-testing 126 



Crystals of Tin 96 



H. T. VUIiTE AND D. W. WARD. 



The Natural Dyes as applied to Wool 48, 157 



F. G. WIECHMANN. 



Sucrose, Dextrose, and Levulose ; their Quantitative Determination 



when occurring together 126 



