December 20, 1894] 



NA TURE 



•85 



portions and constituents of high explosives, it seems desirable 

 that this iiiformaiion shnuld be afforded by the manufacturers to 

 the users of the explosive. 



(3) In the storage of high explosives, it is desirable that every 

 care should be taken to insure their being maintained in a 

 proper condiiion. It i> also certain that these explosives alter 

 in character with age. 



(4) It is essential that similar examinations of the wording- 

 places and precautions which are in force in mines where hlnst- 

 ing-powder is used, should be rigidly observed when a high 

 explosive is employed. 



(5) In selecting a high explosive for use in a mine, it should 

 not be forgotien that the risk of explosion is only lessened and 

 not abolished by its use. 



(6) All of the high explosives on detonation produce evident 

 flame. 



(7) The emission of flame from a blown out shot of a detonated 

 higti explosive is not prevented by the quantity or length of 

 stemming used. 



(8) In the case of a charge of a high explosive which has 

 missed fire, if a short length of stemming (proved up to 8 inches) 

 has been employed, the charge can be detonated by another 

 cartridge of the explosive and additional stemming being placed 

 in the hole in lionl of the original stemming. 



The experiments were carried out under the direction of Mr. 

 J. L. Medley, H.M. Inspector of Mines, and Mr. A. C. Kayll, 

 the Engineer to the Committee. 



The sincere thanks of mining engineers are due to the Institute 

 for bearing the great expense involved by the experiments, and 

 to the many mining companies, associations, and private firms 

 that have rendered valuable assistance in the matter. 



THE UPSALA MEETING OF THE INTER- 

 NA TIONAL Mb. TEOROLOGICAL COMMITTEES 



A T the meetings of the International Meteorological Com- 

 ■'*■ mitiee, held at the University of Upsala, in August, the 

 secretary submitted a brief report, with the questions pro- 

 posed for discussion. A statement of these, with the decisions, 

 follows :■ — 



Inlernalional Buriaic.^K report was presented by Prof. 

 Hildelirandsson, in which the functions and C'lst of such a 

 bureau were considered. The committee decided against its 

 establishment. 



Agricultural Meteorology. — Upon the proposition of Mr. 

 Scott, it « a- decided that the methods employed to distribute 

 weather predictions to farmers, and the results of climatological 

 discussions relating to the crops in the various countries, be 

 published. 



Establishment of Stations for Cloud Observations. — Prof. 

 Hildeb^and^son presented a pamphlet containing a detailed 

 account of the principal methods employed in these investiga- 

 liunp. Tfte committee adopted these resolutions: — 



Since experience shows that the altitude of clouds can be 

 easily determined with sufficient accuracy, the generalisaiion of 

 these invesligalions :n all countries is recommended, preferably 

 by the use ol the photographic process. Observations of direc- 

 tion and relative veliiciiy should be made at as many stations as 

 possible, and measures ol height at a limited number ol suitably 

 distributed stations. 



The value of these investigations would be greatly increased 

 if made at the same ep ch, therefore it is proposed that they be 

 commenced May 1, 1896, and continued for one year. 



The stations already promised are situated in Balavia, 

 France, Norway, Portugal, Prussia, Roumania, Russia, 

 Sweden. United Slates : Blue Hill, and Weather Bureau (six 

 stations). 



Cloud Atlas. — The committee appointed at Munich reported 

 slightly miidihed delinitions of some types in the Hilde- 

 brandsson-K6p|ien-Neumayer Atlas, and submitted photographs 

 and pastels for reproduction in the new atlas, as well as instruc- 

 tions for observing clouds. These were adopted by the 

 Permanent Ccmmiitee after discussion and modification. 

 (See subjoined report.) A special committee, composed of 

 M. Teis-erenc de Bort and Prof. Riggenbach, with Prof. 

 Hildebrandsson as chairman, was appointed to publish the 

 atlas, and the choice of the colour of each place, to represent 



1 Extracted from a rep-^rt by Mr. A. Lawrence Rotch, in ihc December 

 number of the .-hiu-rUan MctioyoU^^ical Journal. 



\ 



NO. 1312, VOL. 5 1] 



as nearly as possible the natural conditions, was left to its 

 discretion. 



More Rapid Transmission of Telegrams. — Dr. Snellen pre- 

 sented a joint report with Dr. Neumayer on this question, in 

 which the necessity of giving the meteorological dispatches 

 (rrecedence over others, by opening a circuit system with the 

 other central bureaus, was urged. The introduction of simul- 

 taneous observations in the various countries was deemed 

 necessary. The committee relerred the matter to the Inter- 

 national Telegraphic Bureau at Berne. 



In more or less intimate relation with this question was 

 a proposition by Dr. van Bebber, on the importance of further 

 experiments in tele-meteorography. Dr. Snellen explained the 

 telegraphic transmission of the traces of self-recording instru- 

 ments by the Olland apparatus, which operates over a short 

 distance at Utrecht. 



.Scintillation of Stars. — At the request of M. Ch. Dufour, 

 this question, which had been the o ject of investig.itions by 

 M. Montigny, of Brussels, was brought before the cummitlee. 

 Further study by him, together with that of M. Ventosa, 

 on the atmospheric movements observed around stars, was en- 

 couraged. 



Maritime Meteorology: — A proposition of the Russian Admiral 

 Makaroff, on the necessity of an international convention to 

 arrange for the discussion of the data contained in ships' logs, 

 was not approved. 



Psychrometric Observations below Freezing. — This question 

 was introduced by Piofs. Hildebrands.son and Mohn. The 

 employment of Ekholm's method for the reduction of mean 

 values was recommended, but a report of further investigations 

 was recpiesied. 



Exploration of Upper Air. — A resolution received from the 

 Congris de la Science de I' Atmosphere, which had recently met 

 in Antwerp, on the importance of the balloon ascents now heinr 

 made at Berlin for meteorological purposes, was confirmed in a 

 more general sense. 



Next Congress. — It was decided to convene a non-official 

 congress at Paris in September 1896. 



The Classification of Clouds. 



In the cloud classification of Hildebrandsson and Abercromby, 

 published in the flildebrandsson-Ivoppen-Neumayer -Vtlas, in 

 1S90, the word "diurnal" is added to the definition of Group 

 D, so that it becomes : — 



D. Clouds formed by the diurnal ascending currents. 

 In this way, the cumulus ari>ing from a mass of aqueous 

 vapour ascending through calm air is distinguished from the 

 nimbus caused by the general ascension of the whole ma.s of 

 moist air. 



With this change the classification of the ten principal forms 

 is : — 



(<z) Detached or rounded forms (most frequent in dry 



weather). 

 {!>) Wide-spread or veil like forms (wet weatl-er). 



A. Highest clouds, mean height 9000 metres. 



(rt) I. Cirrus. 



(/') 2. Cirro-stratus. 



B. Clouds of mean altitude, 3000-7000 metres. 



, . ^ 3. Cirro-cumulus. 



^ ' ( 4. Alto cumulus. 



(b) 5. Alto-stratus. 



C. Low clouds, 1000-20CO metres.* 



(.1) 6. Strato-cuinulus. 

 (/') 7. Nimbus. 



D. Clouds formed by the diurnal ascending currents. 



8. Cumulus. Top, iSoo metres ; base, 1400 



metres. 



9. Cumulo-nimbus. Top, 3000-5000 metres;* 



base, 1400 metres. 



E. Elevated fog, below 1000 metres. 



10. Stratus. 



N.B. — -As the heights of the clouds marked * do not agree 

 with the heights of these clouds found at Blue Hill, Mr. Rotch 

 has asked that the altitude of the low clouds be placed below 

 2000 metres simply, instead of between 1000 and 2000 metres, 

 since the b.ises of nimbus are frequently below 1000 metres ; 

 and also t hat t he super ior limit of the tops of the cumulo-nimbus 

 be raised to 8000 metres. 



The following are desciiptions of the clouds, modified from 

 those in the Hildebrandsson-Koppen-Neumayer Atlas. 



