File:The Röntgen rays in medical work (1899) (14570210290).jpg

Identifier: rntgenraysinmedi00wals (find matches)
Title: The Röntgen rays in medical work
Year: 1899 (1890s)
Authors: Walsh, David
Subjects: X-rays Radiography X-Rays Radiography
Publisher: London : Baillière, Tindall and Cox
Contributing Library: Francis A. Countway Library of Medicine
Digitizing Sponsor: Open Knowledge Commons and Harvard Medical School

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tion is necessary. Another essential to a good spark is thecondenser. A key or commutator is also provided for turningthe current into the coil, or for reversing it when in action. The break or interrupter is an important part of the apparatusof the induction coil. It may be made on various plans, of whichthe simplest is that of the so-called vibrating hammer, A thinpiece of steel armed at one end with a heavy piece of iron is fixedon the base, so that the head of the hammer is exactly oppositethe centre of one end of the soft iron core, at a distance of about-§■ inch. Fixed in the centre of the hammer, on the face awayfrom the core, is a piece of thick platinum wire, and opposite this,on a stout piece of brass fastened to the base, is a screw carryingin its point another piece of platinum. Connections are madeunderneath the base-board, so that the current must pass through * These coils are now made by arrangement with Messrs. Newton and Co.,and sold under the name of Apps-Newton.
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02 H wo HO w Eh O « ■Ph m m « i—iP i—i <j I—IO PnGO w M H W a OO Oh&h <! oO M Xfl Wo J/2 Pa O£ ELECTRICAL APPARATUS AND METHODS 33 the two pieces of platinum when touching each other, into theprimary wire. The current immediately changes the soft ironcore into a magnet which attracts the iron hammer on thevibrating steel, and the two platinum points are separated. Thecurrent ceasing to flow, the core is demagnetized, and no longerattracts the hammer, which falls back to its original position,when the current flows again into the primary and the process isrepeated. There must be an arrangement for adjusting the dis-tance of the hammer from the iron core, and this has been pro-

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