February 3, 1910] 



NA TURE 



411 



Prof. Omori states that the area of violent motion was 

 elliptical in form, and about 30 km. long from north 

 to south and about 20 km. wide. Judging from the 

 form and position of this area, the origin seems to 

 be situated beneath the Straits of Messina, and the 

 directions of maximum motion at several places radiate 

 from a spot within the Straits between Messina and 

 Reggio, and somewhat nearer the latter town. The sea- 

 waves caused the greatest damage along the Calabrian 

 coast from Pellaro to Lazzaro, where many houses were 

 destroyed by them, and the sandy shore-ground to a 

 maximum breadth of 100 metres was swept away. It is 

 remarkable that the sea-waves were greatest at those 

 places where the shock was not most violent. They appear 

 to have radiated from two centres, which may, however, 

 be portions of a continuous zone of disturbance. Prof. 



;. I — Miip showing the mi 

 quakes in Central and So 

 violent motion district of 

 areas, Nos. i-iz, are the < 

 earthquakes. 



1 relations of the great destn 

 ;rn Italy. The shaded area f 

 ^les^ina■Regg^o Earthquake 

 lar districts tor the previous 1 



Omori believes that the sea-waves were principally due to 

 the depression of the ground under the portion of sea in 

 question. This latter action, he says, might consist in 

 the vertical settlement through one or two metres of the 

 loose superficial deposits at the bottom of the Straits, such 

 as was known to occur along the shores. The report is 

 illustrated by some interesting maps and diagrams. One 

 of these, here reproduced (f^ig. i), shows the curved band 

 along which lie the areas of violent motion of thirteen 

 great earthquakes in central and southern Italy. These 

 areas being alinost distinct. Prof. Omori concludes that 

 great disturbances are not repeated from one and the same 

 centre, that Messina and Reggio are therefore compara- 

 tively safe from further harm, while the portions of the 

 seismic band intervening between those mapped are, 

 seismically, the most dangerous in southern Italy. 



NO. 2IOI, VOL. 82] 



Prof. Platania's report on the seismic sea-waves is one 

 of unusual interest and value. According to Prof. Omori, 

 the maximum height of the waves (of io-6 metres) was 

 reached on the Calabrian coast between Pellaro and 

 Lazzaro, but for the opposite coast, at S. Alessio, Prof. 

 Platania gives a height of 117 inetres, or 37 feet. All 

 along the east coast of Sicily the waves were perceptible, 

 though at the northern point (Torre di Faro) they only 

 attained a height of o-S metre, and at the southern point 

 (Capo Passero) of 1-5 metres. Along the north coast they 

 were observed as far as Termini, and along the south 

 coast as far as Porto Empedocle. The limits along the 

 Calabrian coast are still unknown. In the Lipari Islands 

 they passed unnoticed, while they were very conspicuous 

 at Malta. .\t Catania the mareograph was inundated, and 

 the driving clock was stopped by the shock : but good 

 records were given by the mareographs at Malta, Palermo, 

 Mazzara, Cagliari, I'schia, Naples, Civitavecchia, Livorno, 

 and Ravenna. With the e.xception of Cagliari, the period 

 of the oscillations was approximately the same at each 

 place as that of the seiches due to meteorological causes — 

 a coincidence already noticed by Omori and Honda in other 

 cases. The wave-velocity obtained from the formula 

 V=^(gh) is always much greater than the observed 

 velocity by from 25' to 57 per cent. Taking variations of 

 depth, however, into account, the discrepancies tend to 

 disappear. Of the four submarine cables beneath the 

 Straits from Torre del Faro to Bagnara, only one was 

 broken, and this was close to the shore, and was probably 

 caused by the drifting of a ship's anchor. Two telephone 

 cables were broken by the earthqu.ike, one at about 3 km. 

 from Gallico, and at' a depth of 500 metres, the other at 

 about 12 km. east of Vulcano. Interruptions also occurred 

 in the Malta-Zante cable ten and eighteen hours after the 

 '■■hock, and at distances of eightv and fifty-eight miles from 

 Malta. ■ C. D. 



THE MARINE AQUARIUM, MADRAS. 



T^HE JIarine .Aquarium at Madras, which has recently 

 •'■ been thrown open to the public, deserves notice as 

 it is the first institution of its kind in India, if, indeed, it 

 is not the first in the tropics. It owes its inception to Lord 

 .•\mpthill, who, while Governor of Madras some four years 

 ago, drew up in conjunction with Mr. Edgar Thurston, 

 superintendent of the Madras Museum, the first rough plan 

 of a public aquarium. The building, a low, unpretentious 

 brick edifice, is situated on the seaward side of the famed 

 Madras Marina, less than a hundred yards from the sea. 

 The main entrance leads into a large paved area with a 

 central fresh-water pond and fountain, and on either side 

 five tanks with plate-glass fronts, lit from above, each 

 measuring 7X3X35 feet. The entire seaward side of the 

 central area is occupied by a large open tank, at present 

 stocked with turtles (Cheionc midas). On either side of 

 the entrance passage are two rooms designed for committee 

 meetings, for storage of materials, &c., and one of them 

 is at present occupied by the aeration plant. 



With the exception of two tanks for fresh-water fish 

 (at present containing species of Megalops, Ophiocephaliis, 

 Notopterus, &c.), which are oxygenated by living Vallis- 

 neria, the remaining eight contain salt water, which 

 circulates from tank to tank, and in addition are supplied 

 with air from two compression cylinders, forced into each 

 tank through a filter candle. At present the cylinders are 

 filled by hand-pumps, but the use of an oil engine is 

 contemplated. Sea water is conveyed to a covered well 

 in the rear of the aquarium along a pipe filled by hand 

 at the seaward end. From the well it is pumped into 

 filter ]^ds, and from these passes to large elevated cisterns, 

 whence it is distributed to the tanks. The shore water 

 on the Madras coast is so disturbed by the surf that this 

 filtration is unavoidable, though the removal thereby of 

 small organisms is undoubtedly a drawback. The water 

 which has circulated through the aquarium tanks can. if 

 desired, be brought back "to the filter beds and used a 

 second time. 



The director of the aquarium is the superintendent of 

 the Madras Museum, and he is assisted by a local com- 

 mittee. A small admission fee is charged, and already 



