216 Notices respecting New Books. 



It is not merely in courts of justice that this sort of difficulty 

 occurs. All sorts of men in all sorts of ways are now dealing with 

 electrical things, and they have a legitimate desire to understand 

 Electrical technical terms, or at all events to be able, when they 

 use such terms, to use them without making laughable mistakes. 

 It is evident that for such men this book has been written. 

 Probably no term, no name for a unit of measurement of any 

 electrical or quasi-electrical quantity which has ever been intro- 

 duced, either by a committee of the British Association or by the 

 humblest American writer, has been untouched upon in this great 

 dictionary. The thirteen new names introduced by Mr. Heaviside 

 are here to be found, and the editor is to be commended for 

 bringing them before the reader in one short article. There is a 

 separate reference also to each of them. The explanations of 

 such terms as these and of many important terms in use are 

 well given, and in many cases there are quotations from well- 

 known text-books in illustration, and although it would be easy to 

 point out small errors in almost every case, it might be contended 

 by the editor that a short explanation must always be somewhat 

 misleading. There are many concise good descriptions, like that 

 under Cell, Storage. But in addition to the sound explanations we 

 have an enormous quantity of unsoundness. For example, at the 

 end of the article on Acceleration there is a strange jumble of 

 change-ratio equations of units and equations of quantities. " But, 

 since Velocity equals the Distance, or the Length traversed in a 



Unit of Time, V=™. Therefore 



_V_ T_L 



A — m — *m ma, 



T 



or the acceleration equals the length, or the distance passed 

 through, divided by the square of the time in seconds. These 

 formulae represent the dimensions of Acceleration." 



Another kind of carelessness just as common but not nearly so 

 misleading is illustrated by : — " The diacritical current is the 

 current which, flowing through the diacritical number of ampere- 

 turns, will . . ." 



It is probably the same writer who, under the heading Accumulator 

 or Condenser, gives at length the Laws of Accumulation of Elec- 

 tricity deduced by Sir W. Snow Harris. 



From Electric Absorption to Electric Work there are tw r o 

 hundred and forty-eight articles, and each of them is a mere 

 reference like " see Absorption, Electric." There is everywhere 

 much cross-reference like this, which seems rather unnecessary, and 

 when it is considered that we have a series of 73 articles beginning 

 with Current, Absolute unit of, and ending with Current, Variable 

 period of, and immediately afterwards another series of 47 begin- 

 ning with Currents, Action, and ending with Currents, Undulatory, 



