524 



NA TURE 



[September 29, 1, 



of importance occurred. These facts alone justify the appeal of 

 the Chief of the Weather Bureau for an increased grant. His 

 estimate of the money needed to meet the legitimate requests 

 of the agricultural, marine, commercial, and manufacturing in- 

 terests of the States is 1,044,050 dollars, being an increase of 

 160,348 dollars. The present report furnishes abundant evidence 

 that whatever money is voted will be used in making the Bureau 

 of service to the people of the States, and of assistance to the 

 progress of meteorological science. In addition to the usual 

 report upon the administrative work, the volume contains an 

 account of the climatology of the year, and papers upon the 

 rainfall of the United States and the floods of the Mississippi 

 Valley, both of which have already been noticed in Nature. 



The September number of Annalen der Hydrographie wtd 

 maritimen Meieorologie contains two papers of more than usual 

 interest : (i) Yearly isotherms and isabnormals of sea-surface 

 temperature, by Dr. W. Koppen, The author has calculated 

 the yearly isotherms from the best available sources, including 

 those of the Deutsche Seewarte and the Meteorological Office, 

 and in addition to the usual methods of showing simply the 

 warm and cold currents, he has indicated the districts where the 

 surface water is more than 2° C. above or below the temperature 

 due to geographical position. (2) Contribution to the knowledge 

 of wind conditions on the sailing routes between the equator and 

 Cape Horn, by Dr. H. Konig. The data used are principally 

 those collected for the sailing directions issued by the Seewarte. 

 In addition to various tables showing the distribution of wind 

 directions for months and seasons, and referring to different 

 districts, the author has shown graphically for each month and 

 each s^-square the percentages of the three most prevalent 

 wind directions, with numbers showing their mean force, the 

 calms, and the total number of observations from which the 

 results are deduced. Both the above discussions are accom- 

 panied by interesting explanatory remarks. 



Telephonic communication has been established between 

 a number of farms in Australia by means of wire fences. The 

 Australian Agriculturist publishes a note from a correspondent 

 writing from a station near Cobar, stating that it was easy to 

 converse with friends at a station eight miles distant with 

 instruments connected on the wire fences, and the same kind of 

 communication was established over a distance of thirteen miles. 

 A large number of stations are connected in this way, and the 

 system if widely adopted will do much to relieve the monotony 

 of back country life. 



Prof. Zickler, of Briinn, has (says the Electrical Review) 

 conducted an elaborate series of experiments, which show that 

 a telegraphic instrument can be actuated at considerable 

 distances by a beam of ultra-violet light. He employs a power- 

 ful arc lamp as his transmitter, using a screen of glass to produce 

 intermittent flashes of the ultra-violet beam, which embody 

 themselves as dot and dash signals on his receiver. The re- 

 ceiver IS an air-gap in a circuit containing an induction coil 

 regulated to an electromotive force just below the sparking point 

 at the air-gap. As Hertz long ago has shown, a beam f ultra- 

 violet light falling on the kathode of a strained air-gap, near 

 Its breaking-down point, will immediately provoke a discharge. 

 Zickler started by producing this effect over a distance of 2 m. 

 Then, by improving the shape and material of his electrodes and 

 enclosmg them in a chamber of compressed air, he was able to 

 increase this distance to 200 m. This is a remarkable result, 

 and It IS extremely interesting to physicists to learn that the 

 short and easily absorbed ultra-violet light can influence a spark 

 discharge at so great a distance. 



The attention of several physicists has been of late turned to 

 determinations of the thermal conductivity of rocks. A large 

 number of experimental results, chiefly statistical, and obtained 

 NO. 1509, VOL. 58] 



by using" the "Wall method," are detailed by Messrs. B. O. 

 Pierce and R. W. Willson in the Proceedings of the American 

 Academy of Arts and Sciences ; while Dr. Francesco Morano 

 has been engaged in determining the internal and external con- 

 ductivity of the rocks of the Roman Campagna and the correspond- 

 ing fluctuations of temperature of the soil(^/// dei Lincei, vii.). 

 While these experiments lead to purely numerical results. Dr. 

 Lees, of Manchester, in a paper read before the British As- 

 sociation, has succeeded in establishing the fact that pressure 

 produces a marked increase of conductivity in the less closely- 

 grained rocks, especially sandstone. 



The disposal of the town refuse of Naples has led to a lengthy 

 discussion at the meetings of the Reale Istituto d'lncoraggia- 

 mento di Napoli, and the publication of a number of papers in 

 their large annual volume of Aiti. The subject is introduced 

 by Prof. Paolo Boubee, who seems to rather favour treatment 

 by the Arnold-Le Blanc system, or the use of destructors ; though 

 it would appear that the refuse of the Neapolitan streets is too 

 wet, and also too poor in carbon, to burn without the additional 

 consumption of coal. At present the street sweepings are taken 

 and deposited some distance outside the city, and the accumula- 

 tions ultimately used as manure; but the effluvia arising from so 

 large a mass of putrefying matter have become prejudicial to 

 health. It is suggested that the problem might be best solved 

 by a series of experiments on the different alternative methods 

 of disposal; and even the clumsy and wasteful plan of dumping 

 the refuse at sea seems considered deserving of a trial. 



An "Improved form of Hydrometer" by means of which 

 the effect of capillarity is eliminated, is proposed by the Rev. 

 H. O'Toole of Blackrock College, writing in the Scientific 

 Proceedings of the Royal Dublin Society. It is similar in 

 principle to Nicholson's hydrometer, but, instead of one bulb, 

 it has two connected by a narrow stem of the same material and 

 sectional area as that which supports the weight. It is first 

 loaded till the lower bulb is immersed, and then loaded till both 

 bulbs are immersed. The additional weights put in at the 

 second observation represent exactly the weight of a quantity of 

 liquid equal in volume to the upper bulb between the two points 

 of immersion. 



"A Contribution to the Study of Individual Variation in 

 the Wings of ;Lepidoptera " is given by Mr. William L. W» 

 Field in the Proceedings of the American Academy of Arts and 

 Sciences, xxxiii. 21. The paper gives the results of an attempt 

 to find in a particular species answers to the following questions : 

 (i) Is a part developed in any given species in an extra- 

 ordinary manner as compared with the development of the 

 corresponding part in other allied species, more variable than 

 parts which exhibit less specific peculiarity ? (2) Which sex is 

 the more variable ? The species chosen is the moth Thereus 

 abbotii, in which the outer margins of the primaries are ex- 

 cessively irregular and extraordinarily long as compared with the 

 other dimensions of the wings. Measurements were made, for a 

 large number of specimens, of the length of the sinuous margin, 

 the length and breadth of the wing, and the chord of the margin ; 

 and from these the author concludes that, in the moth in ques- 

 tion, the most aberrant dimension of the fore wing is likewise 

 the most variable, in accordance with Darwin's law. The 

 females show, in gei eral, a greater degree of variability than the 

 males ; but in the one markedly aberrant feature under dis- 

 cussion, their variability is less than that of the males. With 

 reference to the first conclusion, the propriety may be ques- 

 tioned of instituting comparisons between the lengths of the 

 jagged contour of the outer margin and the straight lines which 

 determine the actual dimensions of the wings. Mr. Field might 

 with advantage make observations on some other insect in 

 which the length or breadth of the wing was the aberrant 

 feature. 



