. Railway and locomotive engineering : a practical journal of railway motive power and rolling stock . ent begins to flow, increasingin strength as the current increases,and is propagated from the wire likelight from the sun. The speed of for-mation of this magnetic field is thesame as the speed of light, namely,about miles per second, as pre-dicted by Faraday and proved by Consequently when the cur-rent ceases to flow this magnetic fieldceases to exist, not by diminution ofdistance propelled, but by ceasing tobe started from the wire or from theinside. Thus, so long as
. Railway and locomotive engineering : a practical journal of railway motive power and rolling stock . ent begins to flow, increasingin strength as the current increases,and is propagated from the wire likelight from the sun. The speed of for-mation of this magnetic field is thesame as the speed of light, namely,about miles per second, as pre-dicted by Faraday and proved by Consequently when the cur-rent ceases to flow this magnetic fieldceases to exist, not by diminution ofdistance propelled, but by ceasing tobe started from the wire or from theinside. Thus, so long as the current isconstant, the magnetic field is constantand is equal all along the wire. Now it was also found by Oersted thatfrom the power of this magnetic fieldit is possible to reverse the operationand to develop electric current in an-other wire if this second wire was apart of a circuit. Thus, let A be a wirethrough which a current can be sent orstopped as desired by closing or open-ing a switch (this wire will be calledthe first or primary wire) and let asecond wire B. which forms part of an-. FIG. 2. PRIMARY ROTATION CLOCK-WISE, SECONDARY IS THEREVERSE. other circuit, be laid closely parallel towire A for some distance (this is calledthe secondary wire). Now if a currentbe started in the primary A, the forma-tion or throwing out of the magneticfield round A will cause a current inthe secondary B, but in the oppositedirection to the current in A, and only while the current .-V is increasing to itsfull strength, so that when there is nofurther increase in the primary currentA, and therefore no increase in thepower of the magnetic field, there isno current in the secondary wire B, Ifnow the current in .A he suddenly
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectrailroa, bookyear1901
