self up since 1870 to in- use in the larger engraving. defatigable studies in this direction. That his experiments have been crowned with complete success is due, he asserts, to the judicious selection and use of the secondary pile of M. Gaston Planté. THE POLYSCOPE. The illuminating apparatus, or… … Fig. 2. Fig. 3. Fig: 5. Fig. 1.—THE POLYSCOPE. mines, powder mills, deep waters, etc. position, M. Trouvé is able to regulate the flow of the stored-up electricity at will. By the ingenious combination POTATO DIGGER. of these devices the practitioner can always regulate, accord- time, in a metallic…
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