474 



NA TURE 



[March 19, 190,; 



behaved as clinographs, and components of vertical and 

 horizontal movements have not been faithfully recorded. 

 Mr. Imamura gives results relating to the speeds at which 

 earthquake motion has been propagated over the Tokio 

 area. At four stations, from 2 to 10 kilometres apart, and 

 connected by telegraph, seismographs were arranged each 

 of which gave an open diagram on a surface marked by 

 time intervals sent from the Seismological Institute. From 

 the differences in time at which the same wave was recorded 

 .11 different stations, the speed of that wave was determined. 

 The surface velocity arrived at is that V = 3'28 + o'os kiln- 

 metres per second, but as to whether different waves 

 in the same earthquake travel with the same speed, which 

 we think is not the case, we are left in darkness. In a 

 paper on after shocks. Prof. Omori shows that the expected 

 11 calculated number of such settlements for a given period 

 closely accords witli observation. By maps and diagrams 

 \v also shows the space distribution of after shocks, there 

 being, as might be expected, fewer of these disturbances 

 recorded at plates distant from a focus than at those com- 

 paratively near. 



In a paper on pendulum seismographs {Bolletino della 

 Societa Sismologia Italiana, vol. vii.) Dr. Agamennone 

 eulogises the work of the Seismological Society of Japan fcr 

 the revolutionary effect it has had upon seismometrv. F< 1 

 1 ;o years prior to the existence of this Society the ordinan 

 instrument employed to record earthquakes was a vertical 

 pendulum. Subsequently horizontal pendulums wen- used, 

 and seismometers took the place of seismoscopes. The re- 

 sults which have been achieved b) the new types of instru- 

 ments .is recorders of movements that 

 1 an he hit are well known, but the value 

 id the records relating to earthquake 

 motion which has radiated to great dis- 

 tances, beyond timing certain phases of 

 motion, is very doubtful. 



The horizontal pendulum largely used 

 in Germany, Austria and Russia, when 

 recording on slowly moving photo- 

 graphic paper, has been referred to as 

 1 species of delicate seismoscope. To 

 some extent this may be true, but vet 

 it records certain phases of motion, and 

 frequently picks up small disturbances 

 which are not recorded by more cum- 

 bn us M 1 ms ni apparatus. In his paper 

 Dr. Agamennone gives three seismo- 

 grams obtained from ordinary pendu- 

 lums, respectivel) n>, s and 3 metres in 

 length, written upon surfaces moving at 

 i.its nl from 26 to 40 metres per hour. 

 Such sei sinograms show the earthquake 

 vibrations superimposed upon those due 

 to the swinging of the pendulums. For 

 recording earthquakes at great distances 

 from their origins, Dr. Omori not only 

 advocates the use ,,( quickly moving 

 surfaces, but that a horizontal type of 

 pendulum should be employed the 

 period of which should be long. On 

 account of the diurnal and other wander- 

 ings of such a pendulum, for most foundations this period 

 is, however, limited to about thirty seconds. 



Other seismologists have also suggestions, and when it 

 is remembered that in a given earthquake continuing for 

 several hours there are groups of waves with periods vary- 

 ing between a fraction of a second and a minute, it is easy 

 to imagine that this should be the case. 



In short, so far as the recording of the period and ampli- 

 tude of unfelt earthquakes are concerned, seismologists are 

 not in step, and until opinions are less divided, which is 

 nut likely to be the case until more experiments have been 

 made, to impose a type of instrument upon the world for the 

 purposes specified seems likely to prove detrimental to 

 seismometrica! inquiry. 



In the last issue of the Bollcttino of the Seismological 



S01 iety of Italy, vol. viii. No. 6, M. Alippi gives a short 



paper on subterranean sounds. The mysterious detonations 



d in Holland and on the shores of the North Sea 



known as mist poeffers are atmospheric phenomena. These, 



wliii h ma\ he the same as the sounds called barisal gii}is, 

 must not be confounded with sounds originating in the 

 earth. These latter, which by no means necessarily accom- 

 pany earthquakes, are in Italy referred to as rombo, bombio, 

 bonniti and other expressions clearly of onomatopoetic 

 origin. 



The remaining pages of the number contain the seismic 

 register of Italy for March and April, 1001. The late 

 appearance of this register is on account of the fact that it 

 practically includes all observations made upon earthquakes 

 which have been recorded in the Italian peninsula, and as 

 these include world-shaking disturbances, the collection of 

 material from foreign countries occupied considerable time. 



As this publication stands facile princeps amongst its 

 kind, Prof. Pietro Tacchini and his staff are to be con- 

 gratulated on their useful work. 



THE NEW BIOLOGICAL STATION AT 

 PORT ER1X. 



THE sixteenth annual report of the Liverpool Marine 

 Biology Committee, 1 which records the completion and 

 occupation of the new buildings at Port Erin, opens afresh period 

 in the history of this Committee, which was constituted in 

 March, 1SS5, at a public gathering of the local naturalists from 

 Liverpool, Manchester. Southport, Chester and the neighbour- 

 hood, summoned by Prof. Herdman for the purpose. The 

 declared objects were " to investigate the marine fauna and flora 

 (and any related subject such as submarine geology and the 



Fig. i.— Western End of Station, showii g Spawning Pond and Hatchery Entrance. 



physical condition of the water) of Liverpool Bay and the 

 neighbouring parts of the Irish Sea, and, if practicable, to 

 establish and maintain a biological station on some convenient 

 part of the coast." These ends have been kept steadily in 

 view for the last seventeen years. At an early stage of the 

 investigations, in 18S7, the Committee established a small 

 biological station on Puffin Island, off the north ccast of 

 Anglesey, and during the next five years this laboratory was 

 kept up, and dredging and other exploring expeditions were 

 carried on from it. 



Then the centre of the Committee's field work was transferred 

 from Anglesey to the Isle of Man — " from the Mona of Tacitus 

 to the Mona of Cresar." Here a small biological station was 

 built on the northern side of Port Erin Bay and was formally 

 opened for work on June 4, 1892, by Sir Spencer Walpole, then 

 Governor of the island. Notices of the work carried on in 

 this laboratory and of the dredging expeditions in the Irish Sea 



1 Liverpool : Tinling and Co., December, 1902. 



NO. 1742, VOL. 67] 



