igs 



NA TURE 



[June 29, 1893 



Still another course would be for a firm of publishers to bring 

 out a purely physical paper. The stumbling-block here is the 

 question of advertisements. According to Mr. Thiselton Dyer, 

 scientific men are supposed to beunbusiness-like, no doubt with- 

 out reason ; but it may be well to remind them that most 

 journa's live on their advertisements, the reading matter being 

 a necessary evil. It would thus be commercially impossible to 

 ran a purely physical paper, as there is no trade, except to a 

 certain extent elearical engineering, which has much to do with 

 physics. 



It might be better to abandon the idea of a central organ for 

 physics, and to publish a complete set of abstracts. Abstracts 

 to be useful must be very well made, and they must be com- 

 plete. It is very difficult to get good abstracts. The work is 

 laborious and costly when efficiently done. Abstracts are only 

 a developed index, and it would still be necessary that separate 

 papers should be obtainable. Incomplete abstracting is a very 

 common vice. It is not enough to have a few papers brought 

 under a reader's notice : that is good when one is reading for 

 general information in an indolent way, but it is useless in the 

 far more common case in which he wants to know either all that 

 has been done on a given subject, or whether some discovery 

 has been hit upon before. A scientifically worked out subject 

 index is also essential, and, as said before, the abstracts must be 

 practically complete. James Swinburne. 



4, Hatherley Road, Kew Gardens, June 25. 



The Glacier Theory of Alpine Lakes. 



I HAVE read with interest the discussion in Nature on the 

 " Glacier Theory of Alpine Lakes," and I feel constrained to 

 write now, more especially as Mr. Wallace has cited Tasmania 

 as a country, among others, where Alpine lakes are associated 

 with "palpable signs of glaciaion. " Having recently, with 

 Prof. Spencer, of Melbourne University, made a visit to the 

 central lake district of Tasmania, a few «ords about the lakes 

 may not be without interest in reference to the subject under 

 discu-sion. 



The lake district of Tasmania is situated about the centre of 

 the island on the great central greenstone plateau, which attains 

 to a height of 4000 ft. aoove sea level in places. We camped 

 on the shores ol Lake St. Clair, and remained there during the 

 wh lie month of January of this year. Lake St. Clair is about 

 2500 ft. above the sea, and is about II miles long by 2 broad. 

 It occupies a narrow valley between the Olympus Range on the 

 one hand and the Traveller Range on the other. A depth of 

 590 ft. is recorded. Its basin probably lies in sandstone (carboni- 

 ferous ?), the structure of the adjoining mountains being sandstone 

 capped by greenstone (diabase). 



Both Prof. .Spencer and myself, being believers in the glacier 

 theory of Alpine lakes, had half expected to find evidences of 

 glaciation, especially as we had heard of well marked signs 

 being found on the west coast, some 50 or 60 miles to the north- 

 west. However, we could not find the slightest trace of glacia[ 

 action. From the top of Mount Olympus, rising about 2350 ft. 

 above the surface of the lake, we got a magnificent view of the 

 country. The Traveller Range opposite is really the edge of a 

 great greens one plateau, stretching away with a roughly un- 

 dulating surface for miles beyond. The surface of this plateau 

 is studded all over with lakes and tarns of va'ious sizes and at 

 different levels. In other directions, too, lakes can be seen here 

 and there nestling in the valleys. In all we counted between 

 thirty and forty lakes and tarns from the top of Mount Olympus. 

 Two small basins of water — the "Olympian Tarns" — rest on 

 the flanks of the mountain itself. On the opposite side of 

 Olympus from St. Clair lies Lake Petrarch, occupying an oval 

 basin and apparently of shallow depth. This lake is about 

 560 fr. above St. Clair. On the right shore of St. Clair occurs 

 another small lake ( Lake Laura) 50 ft. above the former, and 

 separated from it by a ridge about 3400 yard^ across. 



A characteristic feature of this district are the "button-grass" 

 flats. These are open, marshy expanses covered with " button- 

 grass" {Gymnaschanus spharocephalus) and other plants. 

 They are traversed by numerous little runlets of water, which 

 usually unite into one or more main streams. Here and there 

 in many of them masses of greenstone protrude. Between these 

 "flats "are generally low ridge-; of greenstone covered with 

 Eucalyptus and Banksias, &c. Many of these flats or marshes 

 — as, for instance, those in the Cuvier Valley, at the head of 

 which lies Lake Petrarch— reminded me very strongly of the 



NO. 1235, VOL. 48] 



moorland scenery in the Scottish Highlands, and the plateau, 

 already referred to, with the lakes and tarns scattered over iti 

 surface, might be a scene in Sutherlandshire. But in all our 

 wanderings we did not find the slightest sign of glaciation either 

 in the form of moraines or of striated rock-surfaces. We were 

 not able to examine the lakes on the plateau mentioned, but 

 from its configuration I am confident that evidences of glaciation 

 do not exist. On the west coast, notably about the Pieman 

 River, signs of glaciation are, I believe, abundant, and numeroiu 

 tarns and rock basins are associated with them. Here the 

 neighbouring mountains are not so high as those further inland, 

 and it was probably their proximity to the coast that was the 

 cause, during the last glacial epoch, of glaciers being formed there 

 and not further inland. 



So then, though in Tasmania there are instances of rock-basin 

 lakes being associated with umioubted evidences of glaciation, 

 yet, as I have shown, the glacier theory will not account for by 

 far the greater number of the Alpine lakes on the great central 

 greenstone plateau. I do not propose to put forth any theory 

 to account for these lake-basins, but have put down the above 

 facts in the hope that they may prove of some interest in the 

 question at issue, and to show that at least there are some excep- 

 tions to Mr. Wallace's statement that Alpine lakes only exist in 

 glaciated regions. 



I may add that Lake St. Clair has been accounted for by 

 Gould, who explained it by supposing that a flow of basalt had 

 dammed up the lower end of tile valley in which the lake lies. 

 I am, however, much inclined to doubt the existence of this 

 basalt. Though we traversed the end of the lake where it is said 

 to occur, we did not recognise any basalt. 



It may also be remarked about the "button grass" flats or 

 swamps, that they really occupy rock-basins, and may perhaps 

 be regarded as the analogues of the peatbogs of Scotland and 

 Ireland. All those occurring in the same drainage area seem to 

 be directly connected with each other, and I think there can be 

 little doubt that many of them were formerly occupied by lakes. 



Melbourne Univer.sity, May 7. Graham Officer. 



The Editor having given me the opportunity of reading Mr. 

 Graham Officer's interesting letter, I will make a few remarks 

 upon It. 



It seems to me that, without further information as to the nature 

 of the search for drift, erratics, or ice-worn surfaces, and judging 

 from the statement that the plateau studded with lakes and tarns 

 was only looked down upon from an adjacent mountain summit, 

 we can hardly give much weight to the;positive statements, " I am 

 confident that evidences of glaciation do not exist," and — "as 

 I have shown, the glacier theory will not account for by far the 

 greater numher of the Alpine lakes on the great central green- 

 stone plateau." Some light may perhaps be thrown on the 

 matter by the consideration that the undoubted marks of 

 glaciation in many parts of Australia are believed to have been 

 caused by, comparatively, very ancient glaciers, since some of 

 the glaciated surfaces are overlain by pliocene deposits, while 

 others are believed to be of palasoroic age. If the Tasmanian 

 glaciation was also of pliocene age, most of the superficial in- 

 dications may have been destroyed by denudation, or, if pre- 

 served, may be hidden by vegetation or by alluvial deposits. 

 We must therefore wait for a much more thorough examination of 

 the district and of other parts of Alpine Tasmania before it can 

 be positively stated that no evidences of glaciation exist. 



Alfred R. Wallace. 



Vectors and Quaternions. 



■ I WOULD like to ask Prof. Knott whether there would be 

 any fatal objection to defining the scalar product of two vectors 

 as equal to the product of their tensors into the cosine of the 

 angle between them, so that, if the vectors are 



;>i -I- 7>i + kz^, 

 and 



the scalar product would be 



■«i x.i -\- jfi y-i + Zx H> 

 and not 



If this is done, and, for the sake of associativeness of products, 

 i^ is made equal to - I, the distributive or quaternionic 

 product of two (or more) vectors would be their vector product 



