156 



NATURE 



[December 17, 1691 



Mr. Rose water, who was a distinguished member of the 

 U.S. Military Telegraph Corp-s during the American civil 

 war, and is now President of the Old Timers Telegraphic Asso- 

 ciation, has lately been studying the various Government 

 telegraph systems in use in Europe. The results of his investi- 

 gations will shortly be submitted to what is expected to be an 

 unusually interesting and important meeting of the New York 

 Electric Club. 



A COPY of •' Whitaker's Almanack for 1892 " has been sent 

 to us a few days in advance of publication. Great care has been 

 taken, as usual, to keep the Almanack up to date. Additional 

 space is devoted to educational matters, and for the first time 

 educational progress and occurrences are dealt with in a separate 

 article. There is also a separate article on agricultural educa- 

 tion. Other subjects separately treated are the rise, progress, 

 and achievements of the great lines of ocean steamers, naval 

 gunnery, and the results of the census. Of course, various 

 sections resemble in subject those of former years, but even 

 these are for the most part entirely fresh in substance. In many 

 instances the changes wrought during the interval of a single 

 year are so numerous that scarcely a line of the section in which 

 the subject is treated remains unaltered. 



Owing to his declining to take up his residence in Rio de 

 Janeiro, Dr. Fritz Midler, of Blumenau, Sta. Catharina, has 

 been summarily dismissed by the new Government of Brazil 

 from his post of "Naturalista viajante " to the Museum at Rio 

 de Janeiro. The great services which Dr. Miiller has rendered 

 both to zoological and botanical science during his forty years' 

 residence in Brazil are too well known and too widely acknow- 

 ledged to need dilating on. Dr. F, Miiller is now close on 

 completing his seventieth year ; and Dr. Karl Miiller, of Halle, 

 the editor of Natur, proposes to seize the opportunity of col- 

 lecting from his fellow-naturalists some substantial lecognition 

 of the honour in which he is held. 



Dr. H. E. Hamberg has communicated to the Swedish 

 Academy of Sciences a paper on the radiation of the upper 

 clouds rouad barometric minima, prepared from the cloud 

 observations available at Upsala Observatory for the years 

 1874-89. The arrangement of the highest clouds— cirrus and 

 cirro-stratus— in the form of parallel bands has long been 

 noticed by meteorologists in this country, and various papers on 

 the subject have been written by Mr. W. C. Ley, MM. Hilde- 

 brandsson, Koppen, and others ; and the movements of these 

 clouds, in conjunction with the wind prevailing at the earth's 

 surface, are at times sufficient to determine approximately the 

 direction in which an atmospheric disturbance exists, even with- 

 out the use of synoptic charts. For instance, a barometric 

 minimum often exists in a direction nearly perpendicular to that 

 of the radiation, and, generally, on that part of the horizon where 

 the bands of upper clouds are most dense, or whence they seem 

 to radiate, but it is always necessary to take into account the 

 direction of the wind at the earth's surface. The author draws 

 the following conclusions from his investigation :— (l) The radia- 

 tion of the upper clouds is closely connected with barometric 

 minima. (2) Near a barometric minimum, with the pressure 

 below 29-9 inches, the radiation forms with the radius of the 

 depression an angle of about 70°, the deviation of the radiation 

 from the direction of the surface wind being positive {i.e. to the 

 right), by some degrees, on the south-west of the barometric 

 minimum, and negative on the south-east of it. {3) Further 

 from the barometric minimum, with a pressure of 29-9 inches and 

 above, the inclination to the radius is rather greater, about 75°, 

 except where the barometric minimum lies to the north of the 

 place of observation, in which case it is much lower. (4) The 

 angle formed by the radiation is generally greater in the rear of a 

 barometric minimum, reaching nearly 90° in a high pressure ; on 

 NO. I 155. VOL. 45] 



the other hand, it is smaller in front, especially to the south-east 

 of a minimum, and further from the centre. (5) Compared to 

 the general circulation of the air in a barometric minimum, the 

 radiation of the upper clouds most resembles the direction of the 

 wind near the earth's surface. The meaning of this last sentence 

 is not obvious ; but the other conclusions agree, on the whole, 

 with the views of other meteorologists who have studied the 

 subject. 



The Meteorologische Zeitschrifl for November contains a 

 summary, by Dr. J. Hann, of the meteorological observations 

 taken at Cairo from 1868-88. The observations have been 

 published in extenso, together with a good introduction upon 

 the climate, in the Bulletin of the Egyptian Institute, and although 

 similar observations have occasionally been published before, 

 the present series contains much new and useful material. The 

 most striking feature in the climate of this part of Egypt is the 

 Chamsin, the hot and dust-bearing wind which makes its 

 appearance in March or April for about three to four days at a 

 time, and robs a large portion of the trees of their leaves. In 

 the intervals during which this wind is not blowing the 

 weather is pleasant and clear during spring-time, and the 

 nights fresh and calm. During the summer the north winds 

 prevail, with high temperature, very clear air, and great dryness. 

 Towards September humidity appears with the rise of the Nile, 

 the ground is at times covered with heavy dew, and the heat 

 becomes oppressive on account of the moisture. In October 

 and November fog occasionally occurs in the morning, and rain 

 begins to fall. After this season the temperature is uniform 

 and pleasant. Snow is unknown, fro-t very seldom occurs, and 

 rain is not very frequent. The absolute maximum temperature 

 of the i2t years period was 117° in August 1881, which was 

 also closely approached in May 1880, viz. 116° -4. The abso- 

 lute minimum was 28° -4 in February 1880, and the mean 

 annual temperature was 70° -5. Rainfall is only given for the 

 years 1887-88, in which o 87 and i'67 inches fell respectively. 

 The relative humidity sinks at times even on a daily average to 

 12 per cent., and has been known to fall as low as 3 per cent, 

 at certain hours. Thunderstorms and hail are very rare. The 

 original work contains a long investigation on the connection 

 between the height of the Nile and the weather, a comparison 

 between the present climate and that at the beginning of this 

 century, and several carefully prepared diagrams referring to all 

 meteorological elements. 



The refraction and velocity of sound in porous bodies allowing 

 passage of sound, such as sponge, wadding, felt, «S:c., have been 

 recently made a subject of investigation by Herr Hesehus {Rep. 

 der Physik). His plan was to make a plane-convex spherical 

 lens of iron wire net, and fit it, filled with the porous body 

 (variously condensed), into an aperture in a screen. A pipe of 

 variable tone was sounded on one side, and the behaviour of a 

 sensitive flame noted on the other. From the distance of the 

 focus, when found, could be deduced the refractive index and the 

 velocity in the lens. The refrangibility grows with increasing 

 density of the porous substance, while the velocity on the average 

 is lessened ; the latter is also less, the greater the sound-wave. The 

 author gives details of experiments in which the velocity varied 

 from 146 to 261 metres per second (with ebonite shavings). 

 From an empiric formula which he gives, he makes deductions 

 regarding the propagation of sound in tubes, considered as only 

 a special case of its spread through the pores and passages of a 

 porous body. He hopes further research in this field may 

 do something to elucidate the passage of light and electricity 

 through media. 



The Report of the United States Commissioner of Education 

 has been submitted to the Secretary of the Interior. It says 

 that the usefulness of the Bureau depends directly upon what it 



