CONTENTS. vii 
NUMBER LXXVIII. 
Page. 
Art. XXXV. Observations upon the Practicability of reaching 
the North Pole—with a map; by Isaac I. Haves, M.D., 305 
XXXVI. Review of Marcou’s Geology of North America, - 323 
XXXVII. On the Tidal Currents of New York Bay, near Sandy 
. Hook ; by A. D. Bacue, Superintendent U. 8. Coast Survey, 334 
XXXVIII. On a supposed personal Equation in the Use of the 
Zenith Telescope for Determining Latitudes by Talcot’s 
Method; by A. D. as nen cee U. 5, Coast 
vey, - 343 
XXXIX. Sixth A aa to Dana’ s Minsealaey a ; * the Author; 345 
XL. A New Mode of Making Commercial Caustic Soda ; ss 
Joun M. Orpway, - 
XLI. On the Preparation of some Dies listpiiaion, oe particu- 
larly of Sulphate of Copper; by Prof. Henry bh ari . 
XLII. Geographical Notices. No. 1V, - - - 370 
XLUL On Picric Acids and some of its Salts, itis an > 
tageous Modification of one of the Processes for ig gate it 5 
by M. Carey Lea, of Philadelphia, 3 
XLIV. On Deep Sea Explorations ; by Prof. W. P: Tinie 386 
XLV. Application of Polarized a to the ee : > Dr. 
M. C. WuitE, - . 
XLVI. Correspondence of M. al Nixie Hlasegiaale 
Notices, 393.—Feeding of Steam Boilers with a continued 
supply of pure water, 395.—Electric Telegraph, 396.—Pho- 
tography ; Sensitiveness of Photographic Reagents: New 
Photographic process for the Printing of positive proofs: 
False Diamond, 397.—Silk Worms : Bibliography, 398. 
SCIENTIFIC INTELLIGENCE. 
Chemistry and Physics.—On telescopes of silvered glass and mirrors with ellipsoidal and 
paraboloidal surfaces: On the influence of temperature upon phosphorescence, 399.— 
and separation of arsenic from antimony and zinc: On the separation of 
denum: Crystallization 
Point, by. Prof. Fores, ” gee 
_—Tertiary Basin of White "ait Niobrara Rivers, by F. V. Haypen, M.D., 404— 
Letter from G. Garcia Moreno, to Prof. W. Jameson, relative to the Exploration of 
the Volcano of Pichincha, 408.—Metamorphism : Diprotodon trilobus, a new fossil Mar- 
in Australia: Permian System of England: Peak of Aconcagua: 
giganteus : Iowa Geological Report, 411. 
