February i, 1894J 



NATURE 



321 



Through the liberality of Mr. J. H. Veitch (says the Km.' 

 Bulletin), the Museum of the Royal Gardens at Kew has 

 recently been enriched by the whole of the fine and extensive 

 collection of vegetable products made by him during his recent 

 travels in Japan. The collection is not only very extensive, but 

 it is also very varied, and contains many things quite new to 

 the Museum. 



The Rev. C. W. Langmore sends us a description of a fine 

 lunar rainbow observed by him at Bracknell, Berks, about nine 

 o'clock on the evening of Wednesday, January 17. At a dis- 

 tance of about four or five times the moon's apparent diameter 

 a circle of brilliant white was seen. This was surrounded by a 

 broad band of brown-orange of several gradations. Next came 

 a narrow band of violet, followed by a broader band of green, 

 and a narrower one of yellow. The whole series was encircled 

 by a broad band of brown-orange. 



A MEETING was held at the Society of Arts on Friday last 

 for the purpose of formally constituting an Association of Tech- 

 nical Institutions. Representatives of almost every technical 

 institution in the country attended the meeting. Principal F. 

 G. Ogilvie, Edinburgh, presided, and it was agreed that the 

 objects of the association should be {a) to provide a medium for 

 the interchange of ideas amongst its members ; {b) to influence, 

 by combined action, where desirable, Parliament, County 

 Councils, and other bodies concerned in promoting technical 

 education ; and (c) to promote the efficient organisation and 

 management of technical institutions, and to facilitate concor- 

 dant action among governing bodies, and aid the development 

 of technical education throughout the United Kingdom. The 

 council and officers of the association were elected, and a Par- 

 liamentary committee was appointed to take such steps as may 

 be necessary to secure due representation for technical schools 

 on the Commission for dealing with secondary education, and 

 to watch the progress of legislation affecting such schools. 



The twenty-first annual dinner of old students of the Royal 

 School of Mines was held on Monday. More than 150 guests 

 were present, among them being Profs. W. C. Roberts Austen, 

 Le Neve Foster, T. E. Thorpe, A. W. RUcker, and G. B. 

 Howes, Sir H. Trueman Wood, Sir Lowthian Bell, Captain 

 Abney, Mr. Bennett H. Brough, Mr. W. Topley, Mr. P. C. 

 •Gilchrist, Mr. R. D. Oldham, Dr. E. J. Ball, and Dr. Wynne. 



The weather has recently been very unsettled over the British 

 Islands, owing to the influence of a succession of great atmo- 

 spheric disturbances passing from the Atlantic to the north- 

 ward of Scotland ; strong gales have occurred in some parts 

 daily for more than a week, accompanied at times with thunder- 

 storms and snow or hail. During the latter part of last week 

 reports from the Azores showed that the barometer there was 

 two inches higher than in Scandinavia, and the steel barometric 

 gradients over this country caused the wind to blow with the 

 force of 10 of the Beaufort scale (o- 12) in the north and west, 

 both on Saturday and Monday. Although rain has fallen every 

 day, the amount has only been heavy in exceptional cases; an 

 inch and upwards in twenty-four hours was measured both in 

 the north and south towards the close of the week. In the 

 north of Scotland the fall for the week ended January 27 was 

 much above the average. 



Dr. J. Hanx has just communicated to the Academy of 

 Sciences at Vienna a paper entitled " Contribution to the daily 

 range of the meteorological elements in the higher strata of the 

 atmosphere," containing (l) the calculation of the two-hourly 

 observations of all the meterorological elements on the summit 

 ■of the Ontake in Japan (10,023 feet), from August i to Sep- 

 tember 12, 1891, and at two base stations, with a thorough 

 investigation of the results by harmonic analysis, by which 

 means some interesting differences in the daily range are ex- 

 bibited between the upper and lower stations; (2) the calcu- 



NO. 1266, VOL. 49] 



lation and discussion of the observations made by self-recording 

 instruments established by M. J. Vallot on Mont Blanc (15,770 

 feet), from July to September, 1887, together with observations 

 at Grand Mulcts (9875 feet) and Chamounix (3396 feet). The 

 maximum temperature on Mont Blanc occurred at ih. 30m. 

 p.m., and at the other stations at ih. p.m., but at Geneva it 

 occurred at 2h. 30m. p m. The mean temperature on Mont 

 Blanc from July 18 to August 14 was 20 "5, and at Geneva 

 69°"8. The average decrease with height was therefore i^'i F. 

 for each 100 metres (328 feet) ; the maximum decrease was i°'3 

 at 3h. p.m., and the minimum nearly i°"o at 4h. a.m. The 

 daily range of atmospheric pressure shows that notwithstanding 

 the enormous height the double daily period still occurred. The 

 author then discussed, with the aid of the Bavarian stations, the 

 modifications to which the single daily barometric oscillation 

 with increasing altitude is subject. The analysis shows that the 

 amplitudes first decrease with height, and then increase, from 

 about the height above sea at which the times of the phases begin 

 to run in an opposite way to those at the surface of the earth. The 

 influence of the daily variation of temperature in the strata of 

 air below the mountain summit, is thoroughly discussed on the 

 basis of these results. Dr. Hann points out that it is one of the 

 most interesting results of barometric observations on high 

 mountain peaks, that they show us that daily temperature 

 oscillations in free air are much smaller than those shown by 

 thermometers at stations, even those on the peaks. Meteoro- 

 logical science is much indebted to Dr. Hann for this valuable 

 and laborious investigation. 



Two ways of producing "artificial glaciers" are described by 

 K. R. Koch in Wiedmanns Annaleit. The yellow kinds of pitch 

 resembling colophony, which can be commercially obained, 

 exhibit the plasticity with regard to pressure, and biittleness 

 with regard to tension, that ice possesses, or at least the surface 

 layers do after some exposure to the air. Herr Koch takes a 

 square tray provided with a slanting gutter, down which the 

 pitch is allowed slowly to descend. To prevent its rolling 

 down, the gutter is first lined with a layer of very hot pitch. 

 As the mass descends, fissures are produced in the surface, which 

 show a great resemblance to those observed in ice, though not 

 so deep as the latter. Cracks proceed from the edges towards 

 the middle at an angle of forty- five degrees to the edges, and 

 join the transverse fissures in the centre. Where the bed widens, 

 longitudinal crevices are produced. The black fissures show 

 well in the brown surface. Another method is to coat the pitch 

 with a layer of some white paint, when the cracks appear black 

 on white. It can thus be easily shown that particular forms of 

 cracks always appear at particular parts of the bed. The 

 motion, sometimes uniformly progressive, sometimes pausing, 

 and sometimes directed upwards, can be well studied with a 

 microscope. 



Those who have had occasion to measure an electric current 

 by the deposition of silver on a platinum bowl as kathode, 

 have probably occasionally noticed the very regular manner 

 in which the silver is deposited in radial lines. This appear- 

 ance is particularly noticeable on the sides of the bowl, and 

 when a somewhat strong solution of silver nitrate is employed. 

 Herr U. Behn has conducted an elaborate series of experiments 

 with a view to ascertaining the cause of this regular deposi- 

 tion, and has examined the effect on the deposit produced by 

 the concentration of the solution, the current density, and 

 the potential difference between the anode and kathode. 

 He finds that in the electrolysis of silver nitrate, the effect 

 is best obtained with a concentrated solution of the salt, 

 and when the current density at the kathode is small. An in- 

 crease in the temperature of the voltameter is found to facilitate 

 the formation of the ridges, while, on the other hand, the value 

 of the electromotive force employed seems to e.xert no influence. 



