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No. 101.— THE SEXTANT, and other Reflecting Mathematical Instruments. With Practical Hints for their adjustment and use. By F. R. Brainard, U. S. Navy.
No. 102.— THE GALVANIC CIRCUIT INVESTIGATED MATHEMATICALLY. By Dr. G. S. Ohm, Berlin, Translated by William Francis. With Preface and Notes by the Editor, Thomas D. Lockwood, M.I.E.E.
No. 103— THE MICROSCOPICAL EXAMINATION OF POTABLE WATER. With Diagrams. By Geo. W. Rafter.