February 2, 1^93] 



NATURE 



327 



longitude 72° west and latitude 17° north, between iih. 48m. 

 and 5h. 48m. G.M.T., he deduced the radiant point from 70 

 short-track meteors, and four coincident stationary ones, giving 

 its position as R.A. 28^ decl. +36°. Counts being taken at 

 intervals for areas of 60^, about 18 meteors per minute were re- 

 corded, thus making a total number of 108 for the entire hemi- 

 sphere in one minute, or 6480 per hour. As this fall went on 

 continuously for six hours without any sign of the numbers 

 diminishing, we have the number of meteors 38,880, which 

 Mr. Boraston says must certainly be a minimum, as many faint 

 and rapid ones must have escaped notice. A further observa- 

 ion at 8h. 48m. showed that the action was still being kept up, 

 bus increasing this number to about 60,000. During this display 

 it was remarked that the meteors appeared much brighter when 

 distant from the radiant point than in its vicinity. 



A New Method of Photographing the Corona.— M. 

 H. Desiandres, in the Comptes Kendus of January 23, describes 

 a method of photographing the solar corona without the aid of 

 absorbing media. Sunlight is allowed to fall directly on a 

 system of two identical prisms with parallel and inverted faces 

 placed at a distance apart, such that only a portion of the 

 diverging band from the first is intercepted by the second. 

 After passing through the latter, the rays by recomposition give 

 rise to a well-defined coloured image of the sun's disc. On 

 displacing the prisms in a line perpendicular to the line joining 

 them, the image assumes different colours, and on moving them 

 along it, the range of colours intercepted is made to change. 

 The prisms may be replaced by gratings. In a series of experi- 

 ments carried out during the autumn, nine successive impressions 

 of the sun's image were taken, ranging from the C line till far 

 into the ultra-violet. The object was to find the region where 

 the light emitted by the corona showed the greatest photographic 

 difference from that of the diffused sunlight in the atmosphere. 

 As a matter of fact, a halo distinctly separated from thedififused 

 sunlight showed itself on some of the negatives, especially in 

 the ultra-violet region, which very probably represented the 

 corona. But to confirm this, simultaneous exposures at different, 

 especially elevated, stations ought to be made, if possible 

 during a total eclipse. 



GEOGRAPHICAL NOTES. 



The February number of the Geographical Journal, in addi- 

 tion to two important papers read before the Royal Geographical 

 Society, and already reported in Nature, contains a brilliant 

 account by Mr. Conway of the crossing of the Hispar Pass. 

 The views of mountain scenery were bewildering in their ex- 

 tent ; from the foot of the valley an unbroken glacier was in 

 sight, stretching downward from the pass forty miles distant. 

 This unrivalled ice-stream was covered for the lower twenty 

 oiles with moraines. From the pass a vast snowfield, surrounded 

 by magnificent rock aiguilles, was seen to lie below, and from 

 this the Biafo glacier descended. From the end of the Hispar 

 glacier to the end of the Biafo glacier was a distance of eighty 

 miles, forming the longest snow-pass in the world outside the 

 Polar regions. Mr. Stephen Wheeler communicates a paper on 

 Mendez Pinto, whose early travels in the East seem to have been 

 unduly discredited. 



It is announced that the eminent geographical author M. 

 Elisee Reclus has accepted a professorship in the University of 

 Brussels, and will commence his woik there by a course of lec- 

 tures on comparative geography. 



Mr. Astor Chanler's expedition to Lake Rudolf, by the 

 Tana, has reached Hameye, the Ibea Company's post at the 

 head of navigation on the Tana — a position accessible in five 

 weeks from the coast, to which camels, oxen, donkeys, and 

 horses can be safely taken. Lieutenant Hohnel, who is at- 

 tached to the expedition, finds that Commander Dundas has 

 placed the Tana from 20 to 22 minutes of longitude too far west, 

 and he has searched in vain for the mountain ranges reported by 

 Dr. Peters. 



In a recent journey of some duration in the Sakalava plain in 

 the north-west of Madagascar, M. Emile Gautier (according to 

 the Annales Geo^raphique) found the soil everywhere to consist 

 of a, stiff red clay, weathered into steep-sided lumps and chasms 

 overlying sedimentary rocks, but quite similar in colour and 

 character to the red clay which covers the volcanic rocks of the 

 plateau. M. Gautier believes that this clay is identical with the 

 laterite of the Deccan. 



NO. I 2 14, VOL. 47] 



Major Leverson, the British Commissioner for the delimita- 

 tion of the frontier between the British South Africa Company's 

 territory and the Portuguese possessions, has returned to this 

 country, after having carried out extensive surveys and made 

 considerable rectifications in the map of a strip of country 

 stretching from the north-east corner of the Transvaal northward 

 to Massike^se. The position of the latter point was fixed as 

 i8°i5'33"S.,32°5i'24"E. 



Mr, Mackindf.r gave the second lecture of his coarse on 

 History and Geography, under the auspices of the Royal 

 Geographical Society, on Friday evening, when he discussed the 

 road to the Indies, showing how the desert route, which led to 

 the growth of Palmyra, was superseded by the ocean route after 

 the successful rounding of the Cape of Good Hope. The theatre 

 of history in ancient times was the region enclosed between the 

 pine forests of northern Asia and the Indian Ocean, divided into 

 separate worlds by a double belt of deserts and steppes. 



THE GROWTH OF ELECTRICAL INDUSTRY. 

 (^N Friday last Mr. W. H. Preece, F.R.S., delivered before 

 ^^ the Institution of Electrical Engineers his inaugural ad- 

 dress as President. He said he had completed his fortieth year 

 of continuous service in developing the practical applications of 

 electricity for the use and convenience of man, and it appeared 

 to him that he could not better repay the high compliment the 

 Institution had conferred on him by electing him, for the second 

 time, to be its President than by surveying and criticising the 

 growth of the various branches of electrical industry with which 

 he had been more or less associated during that long period. 

 In the course of his address he dealt with telegraphy, submarine 

 telegraphy, lightning protection, railway signalling, telephony, 

 domestic applications, electro-chemical industry, electric light- 

 ing, power transmission, electric traction, and theoretical views 

 of electricity. 



Speaking of telegraphy, Mr. Preece said : — The instrument 

 that we have principally developed in England is the automatic 

 fast-speed apparatus, based on a principle of preparing messages 

 for transmission by punching, devised by Alexander Bain in 

 1848, and improved in its mechanical details by Mr. Augustus 

 Stroh in 1866. This has been my special pet, and with the 

 electrical assistance of Mr. J. B. Chapman, and the mechanical 

 skill of Mr. J. W. Willmot, all the ills that telegraphs are heir 

 to have been routed, and the practical speed of working has 

 been multiplied more than six-fold. It has been one long 

 continual contest between patient observation, inventive skill, 

 careful experiment, and technical acquirement on the one hand, 

 and resistance, electrostatic capacity, inertia (electro-magnetic 

 and mechanical), bad insulation, impure materials, imperfect 

 workmanship, &c., on the other. But we have, step by step, 

 won all along the line : 75 words per minute have become 500 ; 

 a possible 130 has become an actual 600. Duplex automatic 

 working over cable lines is possible, and modes of working 

 have been introduced that were thought at one time chimerical 

 and impossible. . . . 



The results to which I have referred have not been attained 

 without very special attention to questions of construction and 

 maintenance of the wires, both aerial and submarine, and a 

 very complete system of test is now applied both before and 

 after every line is completed. In the early days of telegraphic 

 communication very rough and crude tests were applied, and 

 the condition of the lines caused serious difficulties ; but at the 

 present day we must ascertain the purity of the metal em- 

 ployed, its mechanical strength, its electrical resistance and 

 capacity, its insulation resistance, and the relationship between 

 the latter and the conductor resistance, as well as its speed 

 value. The employment of copper as the conductor suspended 

 on poles in place of iron, which was inaugurated at my instiga- 

 tion in 1884, by a very costly experiment between London 

 and Newcastle, has had a material influence in increasing the 

 speed of working and improving telegraphy. This is due not 

 only to its reduced resistance, but to the absence of electro- 

 magnetic inertia in a long, single-suspended copper wire. All 

 our long important telegraphic circuits are now built with 

 copper. 



One of the arguments used against the proposed transfer of 

 the telegraphs to the State was the notion that invention would 

 not be fostered by a Government department. This has been 

 entirely falsified. Telegraphy has been advanced in this country 



