July 5, 1888] 



NATURE 



229 



spiders' webs. These caterpillars were different in different 

 cases. In the oak they were species of Tortrix ; in the apple 

 the win:er moth was destructive ; while in other cases the larva 

 of the Ermine moth was exceedingly hurtful to leaves. 



The American Meteorological Journal, desiring to attract the 

 attention of students to tornadoes, in hopes that valuable results 

 may be obtained, offers the following prizes : — For the best 

 original essay on tornadoes or description of a tornado, 200 dollars 

 will be given ; for the second best, 50 dollars. Among those 

 worthy of special mention 50 dollars will be divided. The 

 essays must be sent to either of the editors, Prof. Harrington, 

 Astronomical Observatory, Ann Arbor, Michigan, or A. 

 Lawrence Rotch, Blue Hill Meteorological Observatory, Read- 

 ville, Mass., U.S.A., before the first day of July, 1889. They 

 must be signed by a nom de plume, and be accompanied by a 

 sealed envelope addressed with the same nom de plume and in- 

 closing the real name and address of the author. Three inde- 

 pendent and capable judges will be selected to award the prizes ; 

 and the papers receiving them will be the property of the journal 

 offering the prizes. A circular giving fuller details can be 

 obtained by application to Prof. Harrington. 



The United States Congress has been discussing the question 

 whether the Weather Bureau should be transferred to the pro- 

 posed new Department of Agriculture. Science advocates the 

 maintenance of the existing system. "The observations," it 

 says, "upon which the Weather Bureau bases its calculations 

 are now all made by enlisted men of the army, who have been 

 specially instructed and trained for the work. No political 

 influence whatever has been allowed to operate for their 

 appointment, promotion, or retention in the service. It has 

 been the aim of the Chief of the Signal Office to send to all 

 important stations men who will be acceptable to the communities 

 in which they are to live and do their work, but no member of 

 Congress has been able to secure the transfer or removal of an 

 observer sergeant in order that some favourite might be put in 

 his place. The security which the observer sergeants have felt 

 for the terms of their enlistment has certainly had a beneficial 

 effect upon the character of the service they have rendered. 

 It may seem an anomaly to the people that a duty that is in no 

 respect of a military character should be done by soldiers rather 

 than by civilians, but the military organization of the Weather 

 Bureau has certainly resulted in keeping political influence from 

 dictating in regard to the personnel of a class of men whose 

 appointment and promotion it was very desirable to keep free 

 from this influence." 



The Report of the Director of the Hong Kong Observatory 

 for 1887 shows that the meteorological inquiries are being 

 pushed on with vigour, and that the amount of information 

 collected respecting the typhoons of the past year has been much 

 greater than in previous years. Some of these results have been 

 published in an appendix on the " Results of Further Researches 

 concerning Typhoons " ; and another work on the subject, with 

 maps exhibiting the paths of the typhoons, is in preparation. 

 This investigation will throw light on the cause of the frequency 

 of these storms in the China Sea in September, and will enable 

 masters of vessels to escape damage from them, and to make 

 quicker voyages. 



We have received from Dr. Hellmann a very comprehensive 

 and careful discussion of the rainfall of the Iberian Peninsula, 

 being an excerpt paper from the Berlin Zeitschrift der Gesellschaft 

 fiir Erdkunde, vol. xxiii. The principal results of the investiga- 

 tion were communicated to the Berlin Meteorological Society in 

 January last (see Nature, vol. xxxvii. p. 312). Dr. Hellmann, 

 to whom we are indebted for many laborious inquiries, took ad- 

 vantage of his stay in Andalusia, in 1875-76, to collect all avail- 

 able materials, but found them insufficient for trustworthy results ; 



the present discussion has therefore been delayed until the ob- 

 servations of ten more years could bi added. The work deals 

 with the monthly and yearly values for sixty-seven stations, for 

 which a sufficiently long series could be got, and contains a map 

 showing the yearly distribution of rainfall. The yearly and 

 daily periods of rainfall, the monthly and yearly extremes, and 

 the frequency, are also all fully and ably discussed. The 

 annual fall is very various, being no less than 138 inches on the 

 Serra da Estrella, and as little as 11 inches at Lerida, in 

 Catalonia. In the yearly period the minimum fall at all 

 stations occurs in July and August, and the maximum, generally 

 speaking, about May or October , according to locality. Snow 

 falls only in a few of the more elevated districts. 



The vapour-density of sulphur has been re-determined by Dr. 

 Biltz in the laboratory of Prof. Victor Meyer, with unexpected 

 results. It has hitherto been generally accepted that at a tem- 

 perature (524 C.) not very far removed from its boiling-point 

 (447 C.) the molecule of sulphur is built up of six atoms. This 

 assumption is based upon vapour-density determinations by 

 Dumas and Mitscherlich, who obtained values about this tempera- 

 ture pointing to a hexatomic molecule. However, the work of 

 the last few years upon the chlorides of aluminium, tin, and iron, 

 has opened the eyes of chemists to the fact that the double 

 formulae A1 2 C1 6 , Sn 2 Cl 4 , and Fe 2 Cl 6 , resting as they did upon a 

 few experiments performed within a very limited range of tem- 

 perature, are erroneous, and have no foundation in fact. The 

 older work upon the constitution of sulphur molecules was 

 notably of this class. The experiments themselves were irre- 

 proachable, and completed with all the skill for which the 

 experimenters were famous ; but unfortunately the temperatures at 

 which they worked were not sufficiently removed from each other, 

 there being only a difference of 27° C. between their maxima and 

 minima. It is now, moreover, a demonstrated law that the 

 existence of molecules of fixed composition can only be assumed 

 when the vapour-density remains constant within a notable 

 interval of temperature. Hence a series of fresh determinations 

 have been undertaken in the case of sulphur. Experiments con- 

 ducted at 518 in a bath of vaporized pentasulphide of phos- 

 phorus by Dumas's method gave values averaging about 7 # o, 

 which are nearly coincident with Dumas's own. At the higher 

 temperature of 606 , using a bath of stannous chloride vapour, 

 the density had diminished to 47. At 86o°, as is well known, 

 sulphur vapour attains the normal constitution of two atoms to 

 the molecule, and the density remains constant for about 200 

 higher still. Hence, in order to finally set the question at rest, 

 a series of ten determinations were made at intervals of about 

 io°-i5° from 468 to 606 , with the conclusive result that the 

 density regularly diminished from 7 •9 at the former to 47 at the 

 latter temperature. Hence the notion of S 6 is completely dis- 

 sipated ; there is no more experimental reason for it than there 

 is for the existence of molecules of the constitution S 5 or S„. 

 None but the value corresponding to the normal composition, 

 S 2 , stands the test of interval of temperature, therefore we must 

 conclude that sulphur obeys the usual law, and that its molecules 

 when completely vaporized are each composed of two atoms. 



Science says that the logs from the great raft abandoned off the 

 coast of New England a few months ago have drifted in a direc- 

 tion about east by south, and that the greater part of them are 

 now in the region between the 33rd and 38th parallels and the 

 30th and 50th meridians. The reports lately received at the 

 Hydrographic Office would seem to show that the general drift of 

 the logs has been about east by south, and that most of them 

 are now west-south-west from the Azores. Very few, if any, have 

 drifted north of the 40th parallel. A great deal of timber has 

 been reported further north, to the westward of the 20th 

 meridian, but, from the descriptions given, it does not seem 

 to be a part of the great raft. 



