:7U 



KNOW^LEDGS 



[Sept. 22, 1882. 



the many that may present themselves. Under these cir- 

 cumstances it is not to be wondered at that when 

 hoiul-jiiii efforts are made to guide young men in paths 

 electrical, there should l>e a reatly response to an appeal 

 for pupils. I'ntil recently telegraphy was the only really 

 practical application of electricity, and as tlie Post-office 

 engineering staff is recruited from other branches of the 

 service, the tield was almost limited to the cable companies 

 and the manufacturers. Very great impetus has, however, 

 been given to electrical industries by the invention of the 

 telephone and the secondary battery, and the introduction 

 of electric lighting into tlie domain of our domestic economy. 

 In our issue of the 2nd instant we announced tlie re-opening 

 of the School of Telegraphy and Electrical Engineering. 

 As this is the largest, and the only general, electrical engi- 

 neering school, it can scarcely be said to be invidious if we 

 make a few general remarks upon the institution and its work. 

 Established in iMit^, it is now in its fourteenth year, and 

 tlie progress it has made is remarkable. Intended origin- 

 ally as a school wherein to prepare telegraph engineers and 

 skilled cable operators, it has de\ eloped into an institution 

 of such ambitious dimensions, as to declare its ability to 

 send forth capable men in every practical application of 

 electricity. Submarine telegraphy, nevertheless, still holds 

 a very prominent position in the school, and the apparatus 

 in use is one of the most complete collections in e.xistence. 

 What may be called a uniquilij is the artificial cable, con- 

 sisting of a collection of resistance coils and condensers, 

 so arranged as to exhibit all the phenomena and 

 all the practical difficulties presented by a real oceanic 

 cabl& With good teaching cajjacity, this piece of apparatus 

 is a host in itself, inasmuch as all kinds of imperfections 

 can be readily and correctly imitated in almost any part of 

 the circuit Greater interest, perhaps, may be attached to 

 the apparatus for showing the retardation a current expe- 

 rienws in traversing a long cable. This apparatus consists 

 of a series of resistance coils and condensers, having small 

 receiving instruments at ten different points in the circuit, 

 representing as many stations on the line from England to 

 Australia. The receiving in.strunients are similar to the 

 mirror portion of Thomson's Mirror Galvanometer, in which 

 a ray of light falls upon a very small and almost imponder- 

 able mirror attached to a small magnet capable of rotating 

 around a vertical axis when acted upon by a current 

 circulating in a coil of wire. It is very interesting and 

 eminently instructive to notice these magnets with the 

 mirrors attached moving one after the other, and so 

 indicating the time taken in charging the whole length of 

 wire. 



In telephony, the arrangements appear good, and every 

 effort is apparently made to keep pace with the rapid 

 strides recently made in this branch of the science. Electric 

 lighting promises to afford a very large field, and the 

 managers of the school have done well in securing a C II. P. 

 gas-engine, of an improved make, which they use to drive 

 dynamo machines of the Gramme, Siemens, and Brusli types. 

 Arc lanips of several forms are at the disposal of the 

 students, and in the upper rooms they may Vje seen busy 

 at work making Fitzgerald incandescent lamps, in which 

 the fihiment is made from Swedish paper treated with 

 chloride of zinc. The paper is placed in the hands of the 

 pupils, and they have Uj carry it through every process 

 until the lamp is finished. A number of the lamps are 

 fitted np in a show-room, on the ground-floor, and the 

 uniformity and brilliancy of the light ftmitt<;d by them is 

 evidence, to Ray the least, of can-ful training. Having 

 said thus far of the work of this institution, wc 

 think we may fairly indulge in a little criticism. 

 The protipcctus says that six months suffices to 



turn out good men. Of course, wo must allow 

 the managers to bo better judges than ourselves, but 

 our experience teaches us that an electrician is not so 

 easily made, and that twelve or eighteen months' assiduous 

 labour would not be by any means too much. Electricity 

 occupies a very wide and ever widening field, embracing 

 also a great deal of what may be called speculative science, 

 and a man, however studious and gifted, requires to be 

 possessed of a good groundwork before he can hope to 

 achieve much in general electrical engineering in the brief 

 period of six months. If there is any fault to find with 

 the school itself, it is that it is too electrical, and not suffi- 

 ciently mechanical. We should much have liked to see 

 these embryo engineers doing a little real engineering, 

 making, repairing, and improving all kinds of apparatus, 

 from the magnetic needle upwards. Nevertheless, an elec- 

 trician who entered his prof(>ssion a decade or so since 

 must., on viewing such a building, regard his young com- 

 petitors with a feeling something akin to envy, for then no 

 such advantages were od'ered to the most ardent studerit ; 

 and our hope is that those who go to the School of Tele- 

 graphy and Electrical Engineering to get an insight into 

 a new profession, will appreciate the very advantageous 

 ground they occupy in starting. 



BUTTERFLIES AND MOTHS. 



By W. J. II. Clark. 



WE have now arrived at a slack time for entomologists, 

 as the number of butterflies and moths which 

 gladdened our eyes during last month and the preceding 

 ones has sadly diminished, and very few, comparatively 

 speaking, are now to be found on the wing. Many arc 

 dead, and some have found a comfortable home where they 

 can spend the winter and return to our sight as soon as 

 the warm sun of spring has peeped out. 



The wot weather wo have been having lately has also 

 been greatly against the entomologist, but if it is more 

 favourable during the ensuing weeks, we may expect to find 

 flitting about among the lanes the Small White (Pierih 

 rope), the Brimstone (Gonopteryx rhamni), the Clouded 

 Yellow (CoHas edusn), and the Pale Clouded Yellow 

 {t'oHas J/i/alir), the Comma (Vanessa C. -Album), the Fen- 

 cock (Va7iessa /rt), the Red Admiral {Vanessa Atalanta), 

 and the Brown Hairstreak (Thecla Belulo). 



Among the Si-uinuid.*;, the Humming Bird Hawk 

 {Macroglossa Stellalarum) and the rare Convolvulus Hawk 

 (Sphinx Convolvuli) will be on the wing. 



Very few GEOMETRyK are to bo seen now, but probably 

 the September Thorn (Ennomos erosaria), August Thorn 

 (Ennomos angnlaria), the Vestal (Sterrha sacraria). 

 Autumnal Moth (0/)oral>ia filigrammaria), Many Lined 

 (Phillinhiph'ryr rnrijnnclarin), Treble-bar (Anaitis plagiata), 

 and the Streak (Chesias spartiala), will be taken during 

 the course of the month. 



We may also expect to have the good luck to find the 

 Figure of Eight (DUoha crirnleorephala), Pale Oak Eggar 

 (Trie/dura CraUiyi), Autumnal Bustic (Noclua <jlarrot<a), 

 Mcrveil du Jour (Ayriopis ApriUna), Flounced Ch(!Stnut 

 (Aijriopis pislacina). Lunar Underwing (Agriopis lunosa). 

 Green Brindled Crescent), Misdia Oxyacanlhw), Red Lino 

 (,)uaker (Orlhnsia lota), Black Rustic (Epimdn nigra). 

 Centre Barred Sallow (Cirrhedia a-crampcliiKi), Sullow 

 (Xanl/iia r.nrago). Pink Barred Sallow (Xoiilhiii, kUilijo), 

 Orange Sallow (Xt;runlhia cilrago), Dusky Lemon Sallow 

 (Xanlhia gilvago,) the Brick (Xanlhia ferruginea), Lesser 

 Lute String (Cymalophora dilula), Rosy Rustic 



