390 



NATURE 



{August 25, 1887 



the shore, terminated by a road /eading to the steam-boat 

 pier, and at the end, on the land side, was a good-sized 

 hotel, while between the shed and the lake were gardens 

 with cottages and other buildings. Where once were houses 

 and gardens there is now a kind of bay of the lake. It is as 

 though a pit had been excavated parallel with the shore, 

 which, about 120 metres wide at the water-side, extends 

 inland from 60 to 80 metres, widening as it does so on the 

 eastern side to about 150 metres. This "harbour" is 

 bounded by a low cliff, which rises gradually from a little 

 above the water's edge to a height of about four yards ; 

 the surface, however, instead of being occupied by vessels, 

 is a scene of the wildest confusion : slabs of pavement 

 here, a pile of bricks there, the broken framework of a 

 roof with its displaced tiles, a group of beams, some trees 

 yet living, in one place the wooded gable of a house, pro- 

 ject from the surface of the water, which is covered thick 

 with timber and floating debris. A sadder scene of ruin 

 it would be difficult to imagine. On the land side, part 

 of the pavement of the street yet crests the little cliff, dis- 

 placed near its edge by a series of vertical faults, with a 

 throw of a few inches. Below, large slabs, with the 

 squared blocks still in contact, lie at various angles on a 

 slope of rubbish which j.ist rises above the water. 

 Houses, cracked and shattered, with their fronts in some 

 cases partially fallen, loo'c down on the scene of ruin, and 

 not a few more in the neighbourhood are so injured that 

 they will have to be rebuilt. It is stated that thirty-eight 

 buildings were destroyed in the actual landslip, of which 

 twenty-five were inhabited houses. 



The cause of the landslip is made obvious by examina- 

 tion of the sections which the broken ground affords. 

 That beneath the broken street will serve as an example. 

 Under the pavement for about a yard is a stony deposit, 

 the upper part probably made ground, the lower resembling 

 a coarse gravel. As is natural, it is difficult to decide 

 where undisturbed ground begins : it is enough to call the 

 whole a stony soil, many of the fragments being from the 

 size of the fist to nearly as big as the head. Probably, 

 however, the lowest foot has been little disturbed. 

 Then comes about fifteen or eighteen inches of a well- 

 stratified gravel— rather iron-stained, the pebbles not 

 exceeding a couple of inches in diameter ; under this is 

 about the same thickness of a rather peaty silt — either an 

 old soil, or part of the lake floor, on which aquatic plants 

 have grown ; for v, hat seem to be dead rootlets are 

 abundant. Then comes a thick mass of gray silt. It ex- 

 tends downwards below the level of the lake — probably 

 to a depth of many metres. This it is which has been 

 the prime cause of the catastrophe. The thick substratum 

 of silt, at times little better than a quicksand, has always 

 formed an unsafe foundation. Too heavy a load, either 

 locally by building too large a house, or generally by 

 building many smaller dwellings, any weakening of the 

 cohesion of the mass, exceptional seasons,^ may at any 

 time suffice to pull the trigger of a weapon which, so to 

 say, is always charged. It is doubtful whether this part 

 of the town can ever be regarded as absolutely safe : at 

 the same time there have been but three slips in four 

 centuries and a half, and no doubt precautions will be taken 

 to reduce the danger to a minimum. It is possible that 

 the building of the esplanade has been the immediate 

 cause. Prof Heim, however, does not so regard it, though 

 I cannot say that his arguments entirely satisfied me. 

 However, this is certain, that of the completed building 

 only a few feet were damaged ; the frontage which slipped 

 was that into which piles alone had been driven. 



The most remarkable thing about the slip is that the 

 displacement has been nearly vertical. There has been 

 but little outward lateral movement of the ruined build- 

 it is stated that the. weather changed on the evening of July 5; storms 

 and rain succeeding to a long period cf dry weather. At the time the 

 _'■ ground water" beneath the town was rather above, the lake rather below, 

 Its usual leva!. 



ings. As Prof. Heim words it in the above-named repor 

 " Ground which formerly was from 6 to 2 metres abov 

 the water is now from 2 to 6 metres below it." The silt 

 substratum must have flowed outwards into the deepe 

 water, or in some way been displaced laterally to allow c 

 the surface thus sinking. In accordance with this it i 

 stated that the piles driven for the new wall — which wer 

 fixed in the silt alone — were thrust outwards for distance 

 of from 100 to 300 metres from the shore, and wer 

 pushed up above the level of the water. The catastrophe 

 then, cannot be numbered with the bergfalh, or even wit 

 the ordinary landslips, though perhaps an analogy ma 

 be established with some sea-side slipping of clifts ; but i 

 is none the less lamentable, for, in addition to five death; 

 many families have lost their all — goods, house, and eve 

 the site itself being destroyed ; and great additional ej 

 penditure will be required before the neighbourhood ca 

 be regarded as safe. 



T. G. BONNEY. 



THE NORWEGIAN NORTH ATLANTIC 

 EXPEDITION. 



NOT surpassed by the records of the Austrian Novai 

 Reise, nor by those of our own Challenger Expi 

 dition, is the account of the Norwegian Expedition to tfc 

 North Atlantic, the latest part of which is a Report 

 the Alcyonida, by D. C. Danielssen. Like the other par 

 of this Report the present forms a quarto or rather sma 

 folio volume, and contains over 160 pages of text with : 

 plates and a map giving the details of the geographic 

 distribution. 



The author was one of the staff on board the Va'ringe 

 and he now has the pleasure of describing the specimei 

 collected, but he has not had the assistance of that exce 

 lent zoologist (Koren) whose able work on the Alcyonii 

 of Norway had been executed in partnership wi 

 Danielssen, and whose death all those interested 

 natural science have to deplore. 



The Alcyonids collected during the Norwegian Exp 

 dition are almost exclusively deep-sea forms ; the deptl 

 varying from 38 to 1760 English fathoms. Among the 

 there are no less than nine new genera, which all beloi 

 to the sub-family of the Alcyoninae, with 33 new specie 

 of which two belong to Clavularia, one to Sympodiui 

 one to Nidalia, and the rest to the several new genei 

 There is also a new sub-family with a new genus ai 

 species described. 



The author says quite truly, that, of all the large grou 

 of the Alcyonaria, none have been treated more supe 

 ficially by recent zoologists than that of the Alcyonic 

 No doubt there are many reasons for this ; the delica 

 of their structure, combined with the difficulties of th( 

 preservation in a state for minute investigation, has 

 some extent made their study a difficult one ; and ev 

 the repeated endeavours of Mr. Danielssen to obser 

 them in a recent state were unsuccessful. In regard 

 classification, the author for the moment follows that 

 Milne Edwards ; in this we think he is correct, and ^ 

 thoroughly agree with his reasons ; for until the prese 

 material in the museums of Europe and America has be 

 properly worked out, and much fresh material has be 

 collected, any attempt to give a definite classification 

 the group will be so nruch lost labour. 



In the diagnosis of the genera and species, especia 

 of the latter, the form of the spicules, as well as thi 

 arrangement and position on the polyps, have beenfou 

 of great value, though minuter histological details ha 

 not been used as much as they possibly will be in t 

 near future. One very important and interesting fact 

 mentioned, viz. the discovery in a species of a new ger 

 Voeringia of a nervous system. On the uppermost p: 



I 



