172 



NATURE 



[December 22, 1892 



yet remains for our author, for though " unfortunately no 

 direct evidence of torpidity has ever come under " his 

 own observation, the Dundee Advertiser of April, 1884, 

 supplies him with another straw at which to grasp— not 

 that the newspaper-writer saw it at all in that light, for 

 he called the bird in question a "wanderer," which term 

 is innocently repeated by Mr. Dixon, apparently uncon- 

 scious that thereby he gives up his case, and drown he 

 must unless some one throws him a life-belt. Meanwhile 

 that of the " hibernating" bird is as desperate. Deprived 

 by the brutal sceptic of its ancient refuge in the depths 

 of Lapland lakes, or in the crumbling banks of Persian 

 rivers, in the mud walls of Orkney or in Irish dung-heaps, 

 or even in nests of its own building in sea-girt Schleswig- 

 Holstein, theyf« de Steele Swallow desirous of enjoying 

 torpidity has to betake itself to the security of the Bell 

 Rock Lighthouse, and even there to excite no particular 

 astonishment on the part of the honest men who wel- 

 comed it. If they had looked upon it as the spirit of 

 Robert Stevenson, or -that Abbot of Aberbrothock whose 

 memory was blessed by mediaeval mariners, there would 

 have been some excuse for them, but they simply regarded 

 this Swallow as the proverbial one that doesn't make a 

 summer — it was the 12th of March. They will, we think, 

 learn with surprise from Mr. Dixon that "this bird may 

 probably have spent the winter, dormant, near tlie light- 

 house," while he considers "that we here have the most 

 trustworthy evidence of a positive kind." If this does not 

 indicate hibernation capabilities amongst certain birds, 

 pray to what else can it be attributed?" (p. 16). We 

 leave our readers to answer this question as they please, 

 but we fear their answer will not please him. They may, 

 however, like to know how the incident was recorded in 

 the Migration Committee's schedule by the matter-of-fact 

 observer: — "1884, March 12th. One Swallow (Swift) 

 4 p.m. [Wind] S.E., strong B[reeze] [Weather] cloudy. 

 Arrived much exhausted." No more and no less. 



Returning to the position whence we started we must 

 express our deliberate conclusion that Mr. Dixon, author 

 of so many works as he may be, is no authority on the 

 subject of Migration, which he has left exactly as he 

 found it. In the hope he entertains that his volume may 

 form "a basis for more elaborate study and detailed 

 research " we entirely concur. On one, and that the 

 most wonderful part of the whole business, the faculty 

 whereby birds are enabled to perform their extended flights 

 with such punctuality and general unerringness that the 

 more one knows of the subject the more one is amazed 

 at it, he is silent, for it .would seem that there are even 

 bounds to his imagination, and for this we are thankful. 



DOMESTIC ELECTRIC LIGHTING. 

 Dotnesttc Electric Lighting, Treated from the Consumer's 

 Point of View. By E. C. De Segundo, Assoc.M.Inst. 

 C.E. (London : H. Alabaster, Gatehouse, and Co., 

 1892.) 



THE author of this small volume is of opinion that 

 there is at present no literature obtainable to enable 

 the untechnical public to form a judgment a^ to the suit- 

 ability of applying electrical energy to meet their various 

 requirements, and he states that at present the extended 

 applications of electricity are largely engrossing attention, 

 NO. 1208. VOL. 4.7] 



but owing to the conflicting views expressed by those 

 ignorant or interested, there is a probability of a feeling 

 of disgust being engendered for all things electrical in 

 the lay mind. No doubt there is ^ good deal of truth in 

 this statement ; on the other hand, those who take any 

 interest in this all-important subject will soon learn 

 enough to be able to discern that which is important 

 and worth knowing. The volume under notice has been 

 written in order to fill this want in electrical literature, 

 and to teach the consumer of electrical energy something 

 of the source of the light and power he is using. 



It is admittedly a difficult task to make a technical 

 subject clear to untechnical, though interested, readers, 

 and in this case all the more so, on account of the extreme 

 technicalities of electricity as applied to everyday 

 requirements. 



The author begins at the very beginning, and in Chap- 

 ters I. and II. deals with the lighting of rooms with gas, 

 oil, and electricity, naturally pointing out how very soon 

 the atmosphere is vitiated by the two former illuminants, 

 besides the damage done to paintings, book-bindings, &c. 

 When discussing " How shall I light my house best ? " 

 the author treats of the efficiency and cost of the different 

 illuminants, and points out that although the electric 

 light may be the more expensive, yet the cost per lamp 

 per hour may be fairly compared with oil or gas, because 

 these illuminants are seldom turned completely out when 

 a room is temporarily empty, whereas the facility of 

 switching on and off an electric lamp must naturally save 

 the current and effect economy. 



Chapter III. consists of a short description of some of 

 the systems on which electric light is produced and sup- 

 plied. Great diversity of opinion exists as to which is 

 the best system on which electric energy should be sup- 

 plied for public use. In London two systems are in vogue, 

 viz.. The high pressure alternating current in conjunction 

 with transformers, and the low pressure continuous 

 current system. From the consumer's point of view, so 

 long as the high pressure current is not allowed to enter 

 the house, it matters little what are the conditions ot 

 distribution, provided a continuous low pressure direct 

 supply or a low pressure alternating current from a 

 transformer station is delivered to him, except, of course, 

 where motors are in use, and then the continuous current 

 is a necessity. For installations in the country, separate 

 generating plant is required, and for small installations, 

 where on the average fifteen lamps of 8 c.p. are in circuit 

 at a. time, the author says that the electrical energy can 

 be economically generated by chemical means. The 

 primary battery referred to is a modified form of Bunsen, 

 and the cost of producing the light is stated to be one 

 penny per lamp of 8 c.p. per hour. No doubt such a bat- 

 tery takes the place of engine, dynamo, and accumulators, 

 but it is purely a matter of opinion as to the trouble and 

 skill required to look after these batteries, and, without 

 taking the prime cost into account, a gas or oil engine 

 driving a dynamo and charging accumulators to run 

 these fifteen 8 c.p. lamps should not cost fifteen pence 

 per hour. A case is known where an Otto domestic gas 

 engine is easily driving seven and sometimes eight 8 c.p. 

 lamps, and consuming 24 cubic feet of gas per hour, 

 at a cost of considerably under one penny per lamp, the 

 lamps being run direct off the dynamo. 



