October io, 1895J 



NATURE 



583 



L,.Miif; into <lclails, ii jci.iy !«. s.iul ihat the discussion tended to 

 show that there is little probability of any useful work being 

 done in this direction unless some entirely new departure in the 

 construction of turbines be discovered, Mr. Stoney, however, 

 in his reply to the discussion, gave a sketch of a very ingenious 

 device liy which he proposed to increase the available head in 

 ihe case of its diminution by the rise of water in a river. We 

 think, however, that something more than this will be needed 

 before the Thames weirs become commercially successful as a 

 source of power. 



Dr. Anderson described a rotating fan he had devised, to be 

 used in place of bellows for organ-blowing. The application 

 was successful, as might be supposed in the case where a volume 

 of air, large in comparison with its velocity, was retjuired to be set 

 in motion. A paper liy Mr. Birt, on the growth of the port of 

 Harwich, was interesting from .1 commercial and economic 

 point of view, ami may be taken in conjunction with a note by 

 the President, on the Hook of Holland route. 



.\ description of a railway uji .'^nowdon, which is in course of 

 construction, brought the proceedings of the day to a close. 



On Saturday the proceedings connnenced with the presentation 

 of two reports by Conmiittees of the Section ; the first on 

 standardising, and the second on coast erosion. The 

 standardising report was of an interim character, and does not 

 require extended notice, in prospect of being brought forward 

 again. The c<)ast erosion report was also presented in another 

 Section. Mr. -V. (I. Lyster gave a long description of the 

 ilredging o])erations now going on at the mouth of tne Mersey 

 10 reduce the bar which has too long been allowed to impede 

 the navigation of our great .\tlantic port. 



.\ paper by Mr. K. Hesketh, describing a process of refrigerat- 

 ing by carbonic anhydride, was next taken. This was a very 

 interesting contribution, and afforded a good example of the type 

 ijf paper that should be presented to the Section. It does not, 

 however, lend itself very easily to our present purpose, as it 

 consisted mainly of details of construction of the machinery, 

 which, though highly interesting, it would be impossible for us 

 to make clear without the many illustrations Ijy which the 

 author explained his meaning, .\nother good and characteristic 

 paper was contributed by Mr. \. Napier, who described an 

 installation that has been carried out at Ipswich of the Hermite 

 process of purifying sewage. Briefly stated, the process 

 consists of passing an electric current through sea-water. A 

 jmrt of the chlorides is converted into hypochlorite, and a 

 deodorising agent is thus obtained. The electrolysed water is 

 passed into the drains or sewers. The system, if worked to the 

 lull extent, as proposed by the inventor, would consist of having 

 a separate service of the electrolysed water laid on for use in 

 c-lo.sets, house drains, &c. The system has been in use but a 

 short time in Ipswich, and is said to promise very favourably by 

 those who have been connected with its working. 



The Monday of the meeting is always devoted by Section (i 

 to electrical engineering, and at the recent meeting the proceed- 

 ings on that day, the 1 6th ult., were opened by a long paper from 

 the pen of Mr. I'hilip Daw.son, on the modern application of 

 electricity to traction ])urposes. -Mr. Daw'son has evidently 

 travelled much in the United States, and has there collected a 

 vast amount of data bearing on the subject of his paper. To 

 attempt to follow him into the details he gave in his paper 

 would be hopeless in this report. He is a strong advocate of 

 the trolley system of tiansmission, holding that it will supersede 

 ill others ; and indeed experience in .\merica goes far to bear him 

 "Ut in this. It is needless here to point out how great has been 

 the progress made in the United States in tramway propulsion 

 by electricity ; but one fact stated at the meeting may be repeated, 

 as it puts the whole matter very forcibly. It was said that it is 

 becoming a great prolilem what is to be done with the horses 

 that are being pushed out of the field by electricity. In some 

 places they are being killed for the sake of their hides and 

 tallow ; whilst in other districts go()d horses were to be bought 

 at two dollars each. The latter figure we think may be open 

 to question, for surely a dead horse is worth more than 

 two dollars. However, there is no doubt that electric traction 

 has made immense strides in America, and has in great 

 cities practically supplanted not only the horse and mule, but 

 is fast edging out its mechanical rivals the cable and steam 

 engine. 



The next item on the agenda was a paper by Messrs. Preece 

 and Trotter, on an improved portable photometer. This paper 

 was listened to with great interest ; Mr. Trotter illustrating his 



NO. 1354, VOL. 52I 



remarks 1.) examples of the difTerent forms and apijaratus he had 

 devised for street work. The paper began by a definition of 

 what is meant by illumination. When light falls upon a surface, 

 that surface is said to be illuminated. The illumination depends 

 simply upon the light falling on the surface, and has nothing to 

 do with the reflecting power of the surface, just as rainfall is 

 independent of the nature of the soil. It depends also on the 

 cosine of the angle of incidence. The lighting of streets and 

 of buildings may be specified by the maximum and minimum 

 illumination. The primary purpose of an illumination photo- 

 meter is to measure the resulting illumination produced by any 

 arrangements of lamps irrespective of their number, their height, 

 or their candle-power. The instrument under notice consisted 

 of a box, on the upper surface of which is a diaphragm of white 

 cartl jiainted with a whitewash of magncsi.a ancl isinglass. It has 

 one or more star-shaped ]x;rforations. Immediately below it, 

 within the box, is a white screen capable of adjustmeYit at 

 different angles and two small electric lamps of diflferent candle- 

 power, either or both of which can be used. A portable 

 seccmdary battery is used to supply them with current. The 

 illumination of the hinged screen inside the box varies 

 approximately as the cosine of the angle of incidence of the 

 light from the electric lamps upon it. A handle with a pointer 

 moving over a graduated scale is connected to the screen with a 

 system of levers, and the inclination is so adjusted that the 

 illumination of the screen is equal to that of the perforated 

 diaphragm, the perfi)rations seeming to disappear when this 

 b.alance is affected. The illumination can then be re.-id off on 

 the scale in units of the illumination due to one standard candle 

 at one foot distance. The object of the levers is to give an open 

 and convenient scale. The scale is graduated by experiment, 

 and does not depend upon the the cosine law. The colour 

 difficulty, where arc light or daylight is to be measured, is 

 reduced by the use of a yellow-tinted diaphragm and a blue- 

 tinted screen, the tints being selected .so that the readings arc the 

 same as the mean of a large number of measurements made with 

 white screens. By means of a graduated quadrant and a 

 gnomon the angle and the cosine of the angle of incidence of the 

 light from a lam]) may be measured. Rides are given for 

 deducing the height of the lamp and the slant height, and hence 

 the candle-power of the lamp. 



The discussion on this paper was of a very brief nature, and 

 elicited no new facts of importance. 



Mr. H. A. Earle read a jjaper on storage batteries, dealing 

 chiefly with the chloride b.attery which has lately been intro- 

 duced, and which, it is claimed, possesses the advantages of 

 other and earlier types without many of the attendant dis- 

 advantages, chiefly from the fact that an oxide i)aste is not used. 

 .•\ mixture of chloride of lead and chloride of zinc is cast into 

 small tablets, which have cast round them at high [pressure a 

 frame of anlimonious lead. The subsequent elimination of the 

 chloride and zinc leaves a porous structure of pure lead of a 

 crystalline nature, good conductivity, and with a large surface 

 exix)sed to the electrolyte. The result is a large capacity for a 

 given weight and space occuijieil. 



At the last sitting of the Section, held on Tuesday, the 17th 

 ult. , nine papers were read and discussed. We must deal with 

 these very briefly. The first was by Mr. P. V. Luke, and was 

 entitled "the field telegraph in the Chitral campaign.' It 

 w.as of a poinilar nature, and was illustrated by magic lantern. 

 Mr. (I. Johnstone Stoney explained, by the aid of the ap]Mratus 

 itself, a movement designeil to attain astronomical accuracy in the 

 motion of siderost.ats. Without the aid of diagrams it w.mld 

 not be possible to explain the mechanism, and we will leave it 

 therefore for the jirescnt. A paper by Mr. K. W. Turner 

 explained the modern process of preparing flour from the wheat 

 berry by means of metal rollers in place of the old millstones. 

 The paper was very interesting and treated the whole subject 

 throughout, illustrationsof the various machines used being hung 

 on the walls. Mr. J. Sovithward gave an interesting description 

 of the Linotype process of printing, describing in detail and by 

 the aid of illustrations the really wondeiful machine which h;is 

 been devised for the purpose. Mr. R. E. Crompton, in a 

 memorandum on the B. .\. screw gauge for small screws, pointed 

 out the advantage that would follow if complete uniformity were 

 observed among manufacturers in this matter, and <hvelt on the 

 desirability of a staiulard jilate being provided fijr the purpose 

 by the Board of Traile. .Mr. John Key contributed a paper 

 describing the differences in the practice of English .ind foreign 

 Government departments aiul registration societies in their 



