Thomas Hall
Published: 2016-10-13
Total Pages: 50
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Excerpt from Illustrated Catalogue of Electro-Medical Instruments: Manufactured and Sold by Thomas Hall, Successor to Palmer and Hall, Electrician, Manufacturer and Importer of Magnetic Galvanic, and Telegraphic Instruments The manufacturing of Magnetic and Galvanic Instru ments was first commenced in this country by Mr. Daniel Davis, Jr., in the year 1836. Previous to that time, all the Galvanic Instruments used in this country were imported from Europe. Mr. Davis, having had an old induction coil to repair, saw the principle upon which it acted, and made one for amusement, with some improvement upon the one he repaired. He found a ready sale for it. This induced him to engage in the manufacture of them. At that time they were very rough and inconvenient instruments, com pared with those we now make. They ware very seldom used for medical purposes. The mode of breaking the cur rent was by means of a ratchet placed on the top or by the side of the coil. This was a great objection to them for medical purposes, as the Shocks came very irregularly; this was remedied by the invention and adoption of the vibrat ing armatures in connection with the secondary coils con trived by Mr. Davis. It is now universally used for this purpose both in this country and Europe. By this in genious arrangement the instruments are self-operating, and the current is extremely fine. Making induction coils led to making models for motive power, and various pieces of apparatus to illustrate galvanism and electro-magnetism. The adoption of this branch of physical science in our 001 leges and schools created a constant demand for this class of instruments, so that we now manufacture over five hun dred distinct instruments adapted to this branch of studies. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
