Feb. 12, 1880] 



NATURE 



35* 



THE STUDY OF EARTHQUAKES IN 

 SWITZERLAND 

 A LTHOUGH much has already been done for the inves- 

 ■**■ tigation of earthquakes, it must be admitted that yet 

 more remains to be done, and that we are very far from what 

 might be considered as a scientifically organised system 

 of observations of earthquakes. Therefore all lovers of 

 science will be much pleased to see that the sixty- first 

 meeting of Swiss Naturalists, which was held in 1878 at 

 Bern, appointed a special commission for the study of this 

 important subject. The Commission, which consisted of 

 Prof. Forster, of Bern, as president, Prof. Albert Heim, of 

 Zurich, as secretary, Professors Ainsler, of Schaffhausen, 

 Forel, of Morges, Hagenbach, of Basel, Soret, of Geneva, 

 and M. Billwiller, Director of the Statistical Board of 

 Zurich, chose the telluric Observatory at Bern as its 

 central board, and, after having put itself into communi- 

 cation with foreign observers, it began with the elaboration 

 of a scheme for the organisation of a wide system of 

 observations on earthquakes in Switzerland. 



The scheme elaborated by the Commission is to provide 

 two or three chief stations (Bern, Basel, and, if possible, 

 Geneva) with first-class seismometers, and then to 

 organise a wide net of second-class stations provided 

 \vith simpler instruments. As to the latter three different 

 apparatus were proposed, and will be submitted to experi- 

 ment. Prof. Amsler's seismometer is a pendulum, pro- 

 vided at its extremity with a pencil which draws a line on 

 a blackened paper when it is set in motion by a shock of 

 earthquake; the time of the shock is determined by 

 connecting the pendulum with a clock which is stopped by 

 means of an electrical current as soon as the pendulum is 

 set into motion. The apparatus of Prof. Forster is the 

 common mercury seismometer, but the usual cup with 

 mercury is replaced by two Y-like glass tubes, the upper 

 branches of which are directed to the four chief points of 

 the horizon. Finally, the seismometer of Prof. Hagenbach 

 is the simplest one ; it consists of three hollow metallic 

 cylinders with heavy tops, which are placed vertically 

 like skittles; on a simple plank, when the plank is brought 

 into motion by a shock, the cylinders fall down, and show 

 the direction of the shock (rolling being prevented by a 

 layer of sand which is strewn on the plank), and as they 

 are of different sizes, it is only the smaller one which falls 

 when the shock is feeble, and all three when the shock is 

 a strong one. We do not know what results might be 

 attained by means of the cylinders, but we fear that the 

 pendulum and the mercury seismometers will prove far 

 more difficult to manage, and that they will give less 

 satisfactory results than might be expected. In every 

 case these seismometers will be submitted to a thorough 

 trial before being introduced into practice, and Prof. 

 Forster has already constructed a special apparatus for 

 trying them. A thick plank, ijo lbs. weight, is suspended 

 in a room on three strings, and, the seismometer being 

 placed on it, shocks of various intensity are communicated 

 to the plank by means of a heavy lead-pendulum ; 

 moreover, we daresay that an earthquake will not be 

 long in coming to tell what is the practical value of the 

 new instruments. 



Besides, the Commission has taken steps to interest 

 the public in this class of observations, and Prof. Heim 

 has just published a pamphlet on the nature and causes 

 of earthquakes, and on the means of observing them 

 without instruments. This pamphlet, which will be 

 translated into French by Prof. Forel, will be sent to all 

 members of the Swiss Society of Naturalists and of the 

 Alpine Club, as well as to the meteorological and tele- 

 graphic stations and to the editors of all Swiss news- 

 papers. Further, special leaves, containing each a series 

 of questions on the chief features of an earthquake, are 

 printed, and they will be sent in great quantities through- 

 out Switzerland. The whole country is divided into 

 seven regions, each member of the Commission being 



intrusted with one of them ; and as soon as the news- 

 papers announce an earthquake, the member of the 

 Commission in whose region it has occurred immediately 

 sends the printed leaflets with questions to all persons 

 who might give any information about it. All informa- 

 tion is represented on a map and inscribed in a special 

 book, another book being used for collecting all informa- 

 tion about former earthquakes. 



Such are the important steps taken up to the present 

 by the Commission, and we hope that soon a widely- 

 spread organisation will afford us detailed and accurate 

 information on all earthquakes in Switzerland. 



THE HISTORY OF VESUVIUS DURING THE 



YEAR 1879 

 pROF. JOHN PHILLIPS, in his admirable mono- 

 ■*■ graph on Vesuvius, has given a history of the 

 mountain from the earliest times to the end of the year 

 1868. Palmieri, in his detailed description of the erup- 

 tion of 1871-72, continued the history to the end of the 

 latter year; and in Nature, vol. xix. p. 343, the present 

 writer has described the comparatively uneventful life of 

 the volcano from 1873 to the end of 1878. The past year, 

 although unmarked by any special and paroxysmal dis- 

 turbance, has furnished facts not unworthy of record. 



It will be remembered by readers of the former article 

 on the subject, that at the conclusion of the great eruption of 

 1872, a vast abyssmal crater, 250 metres deep, and nearly 

 as many in diamerer, was left in the great cone of 

 Vesuvius. After three years of comparative rest, during 

 which carbonic acid, sulphurous acid, and ultimately 

 hydrochloric acid, were evolved from fumerole^ in the 

 bottom and sides of the crater, a deep chasm opened on 

 December 18, 1875, from which dense volumes of smoke 

 issued. At night the smoke could be seen to be illumi- 

 nated by the reflection of the light emitted by the molten 

 lava within. A small eruptive cone was soon formed 

 over a portion of this chasm, which increased in energy, 

 and emitted small quantities of lava. On the night of 

 November 1, 1878, the lava which had spread itself over 

 the floor of the crater of 1S72, rose to the lowest portion 

 of the edge of the crater, and commenced to flow down 

 the great cone in a north-westerly direction, towards the 

 Atrio del Cavallo. The secondary cone rose to a height 

 of about 20 metres, and exhibited a fair amount of 

 dynamic activity when I visited it on December 29, 1S7S 

 {v. p. 344, loc. cit.). 



During 1879 small lava streams appeared from time to 

 time on the sides of the great cone, sometimes flowing a 

 little distance downwards in a north-westerly direction, 

 and occasionally towards the north-east. Prof. Palmieri, 

 in a MS. account of " II Vesuvio nel 1879," with which he 

 has been so good as to furnish me, asserts that the energy 

 is markedly greater at the time of the new and full 

 moon. On December 17 the energy increased consider- 

 ably, and a small stream of lava flowed down into the 

 Atrio del Cavallo. When I saw the mountain during the 

 last days of the year it emitted great volumes of smoke, 

 but there was no lava flowing, and but slight illumination 

 of the smoke at night. Towards the nth of this month, 

 however (new moon), the energy increased, and on the 

 13th I ascended the mountain, and witnessed a consider- 

 able augmentation of activity. 



We reached the ob-ervatory at n a.m., when we found 

 that a tramontana, which was blowing strongly at the 

 foot of the mountain, was here so violent that it was 

 questionable whether it would be advisable to attempt the 

 ascent. Moreover, the temperature of the wind was 

 — 3 C. (264 F.), and it blew with intermittent gusts of 

 great violence. However, the guide determined to make 

 the attempt, but he asserted that it would be impossible 

 to ascend the cone by the usual path which proceeds 

 nearly due west from the observatory, as the wind was 



