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action already alternate currents apparatus armature arrangement attracted axis axle battery Berlin cable carried centrifugal governor circuit clockwork coils communication conductive connection conductor consequence considerable construction contact screw copper corresponding current passes cylinder described directed currents disc distance dynamo dynamo-electric machine earth effected electric current electric light electric telegraph electro-magnet employed engine fixed forward friction galvanic Gramme machine gutta percha HALSKE'S holes increase induction inductor inserted instrument insulated invention iron latter lever g line wire local battery magneto-electric means measure mechanical messages methane Morse motion moved necessary needle opposite direction overhead lines paper strip patent plate pointer position of rest pressed printing produced railway relay resistance ring roller scientific selenium side Siemens and Halske signals solenoid spring station steel magnet sulphate telegraph thereby tion toothed traversed tube turned underground velocity of rotation wheel whilst windings zinc
Page 595 - The general reader need not be deterred from taking up the book by the fear that he will have to wade through chapters of long technical terms which he does not understand. Whether he is describing his simple home life or his scientific career and its manifold achievements, Von Siemens writes plainly, unaffectedly, and in a uniformly attractive fashion. The whole work is, as the publishers of the translation say with truth, 'rich in genial narrative...
Page 595 - ... terms which he does not understand. Whether he is describing his simple home life or his scientific career and its manifold achievements, Von Siemens writes plainly, unaffectedly, and in a uniformly attractive fashion. The whole work is, as the publishers of the translation say with truth, 'rich in genial narrative, stirring adventure, and picturesque description,' and stamped throughout with the impress of an original mind and a sterling character.
Page 411 - ... magnet, he submits it to the influence of magnetism whilst it is traversing a glass prism in the direction of its length. This prism, terminated by two square and parallel bases, the surfaces of which are well polished, and which are those by which the polarized ray penetrates and issues from the prism, is placed between the poles of an electromagnet in such a manner that its length and, consequently, the direction of the transmitted ray are parallel to the line joining the magnetic poles. Lastly,...
Page 358 - The well-known fact that the electric current driving an electro-magnetic machine (motor) is considerably weakened by the induced currents produced in the windings of the electro-magnets, made it appear probable to me that by driving a properly constructed electro-magnetic machine backwards, the slight magnetism remaining in the electro-magnets must be considerably increased since the induced currents are then produced in the same direction as those due to the existing magnetism. Experience confirmed...
Page 35 - The movement of the upper one was shown by an index, that pointed to the right or to the left according to the direction of the motion.
Page 344 - An experiment with fresh butchers' meat will give a very good illustration of the chemic part of these phenomena as they occur within the living body. Experiment I. 1 —Procure a half-pound of beef-muscle; insert into it two ordinary steel needles, one connected with the positive pole and the other with the negative pole of a good battery, and pass through the meat from 100 to 200 milliamperes for two minutes.
Page 358 - ... -the current from the magneto was led round the electro-magnets of the other machine. In this way, the magnetic field in which the armature of the large machine rotated, was very much stronger than it was possible to obtain with .permanent magnets. " The technical knowledge of the production of electric currents by means of mechanical power had extended thus far," says Siemens, " when I succeeded, in the autumn of 1866, in obviating entirely the need of steel magnets.
Page 529 - ... known and was described by Lippmann in his early papers. The displacement may be produced by applying a pressure difference between the ends or by inclining the tube ; it may equally well be effected by momentarily inserting a small electromotive force in the circuit. In each case the displacement is a measure of the quantity of electricity which has traversed the electrometer. If we remove the short-circuiting wire and connect B with the earth, then any charge Q given to A will cause a displacement...
Page 29 - Frankfort-on-Maine (a distance of 445 English miles), and another line from Berlin to Cologne is completed as far as Magdeburg. In Hanover, and other states of Germany, the same description of telegraph has also been adopted. This great length of copper wire is coated by means of one single machine which has been constructed by Mr. Siemens and a Mr. Halske conjunctively. It consists of a horizontal cylinder, with a...
Page 27 - I feel called upon to place before the public an account of similar and very conclusive experiments which have lately been tried on a large scale by the Prussian government under the direction of Mr. Werner Siemens, an officer of the Prussian arsenal ; and I wish to avail myself of your valuable assistance for that purpose, knowing how deeply you feel interested in the progress of the science of electrical engineering.