NOTICES. 



LEWIS'S CIRCULATING SCIENTIFIC 

 LIBRARY.— We have received from Mr. H. K. 

 Lewis, of Gower Street. London, a sup[)lementar\- 

 catalogue, covering works added to the hbrarv during 

 the years 1908 and 1909. The catalogue is published 

 at si.xpence, ' and contains a classified index of 

 subjects with the authors who have written upon 

 them, as well as an alphabetical list of titles. We 

 have on pre\'ious occasions called tlu' attention of 

 our readers to the completeness of this librarw and 

 the inducements it offers to students of science. 



be produc(-'d Iw them in rooms, while the other shows 

 how electric it\- can be pressed into domestic service. 

 Our illustration shows one of the demonstration 

 rooms. Beginning on the extreme left we find that 

 the first ceiling light illustrates the method of down- 

 ward reflecting b}' means of an opaque reflector. The 

 second shows one in which there is a white silk 

 shade beneath the lanii> to diffuse the light below and 

 produce upward reflection. The fourth, with the 

 bell-shaped shade, illustrates a method of concentrat- 

 ing all the light and reHecting it downwards. The 



1 >riiii initiation Roimi at the Westminster IHectric Supply Corperation. 



Mr. Lewis has asked us to mention that bis premises 

 ^\•ill in future be closed at 6.30 p.m., instead of 

 7 p.m., during the months of June, July and August, 



A NEW DISCOVERY.— Smoked glasses, it has 

 been shown, onlv cut off a part of the ultra-violet 

 ra\s, which are those which have an irritating effect 

 on the eyes of man}- people ; they also are harmful 

 as they make the retina more and more sensitive to 

 light. A new glass which has been called "Spectres " 

 has been introduced by Messrs. W. Watson & Sons, 

 of High Holborn, which cuts off the ultra-violet rays 

 and yet allows all the remainder to pass freely. It 

 has a pale green tint but it is the chemical con- 

 stituents upon which its p(;culiar properties depend, 

 and eye-glasses made from it have not the disfiguring 

 effect of the ordinary smoked ones. 



ILLUMINATION.— A very interesting exhibi- 

 tion is now open at the offices of the Westminster 

 Electric Supply Cor[)oration, Limited, in Ecclestone 

 Place, Belgravia. One part of it deals with \arious 

 systems of electric lighting and the effects which can 



hith shows upward reflection anel slight downward 

 diffusion by means of an opal shade. The seventh 

 gives diffused light by means of holoj)hane glass. 

 The effects of lighting by means of tnetai filament 

 lamps hidden behind the cornice are also well seen. 

 The candle lamps are used for reflecting from the 

 walls, and the brackets below them are intended for 

 downward lighting. 



On the other side of the exhibition we have an 

 elaborate display of the apparatus which is being 

 perfected in connection with cooking b\- electricity, 

 and an experienced cook is in charge to demonstrate 

 its use. Amongst the exhibits are ranges, ovens, 

 grills, breakfast cookers, kettles and apparatus for 

 giving continuous hot water supply at very small 

 cost. There are also methods of introducing warm 

 fresh air. for keeping towel rails sufficienth' hot to 

 air the towels, and motors for working sewing 

 machines and floor polishers as well as soldering 

 irons, hair driers, and curling tongs which are 

 themselves heated Iw tlie current as the\- are used. 



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