NATURE 
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ae te Peed i ee tae 
* V4 ee ght ayo ok a tae 
‘ 
162 
sk if it is impossible to find in the old world wealth and 
cl enough Brcane one small branch of Prof. Henry’s excel- 
lent work. I refer to the Smithsonian system of book exchanges, 
and I wish to know how much longer it is to continue easier and 
infinitely cheaper to exchange publications with one’s corre- 
spondents in the other hemisphere than it is between London 
and Paris. Let me give an actual case. I recently sent two 
identical parcels of books, one to Utrecht and one to Washing- 
ton. The former cost 5s. 6d., the latter cost nothing. In order 
that no one may run away with the idea that it would cost any 
very large sum to carry out this suggestion, I may remark that 
the Smithsonian system which is on a large scale, with agencies 
at Leipsic, Stockholm, Christiania, Copenhagen, Amsterdam, 
Paris, Milan, London, and Melbourne, besides its American 
ones, only costs 1,000/, per annum. We have only to copy on a 
diminished scale and to utilise existing agencies. 
G. J. Symons 
[See our note this week referring to an institution established 
at Haarlem, —ED. ] 
Dr. Cohn’s Address 
THERE isa passage in Dr. Cohn’s address as reported in the 
Christmas number of NATURE (p. 137), which greatly needs 
correction ;— “Ts ‘ 
‘Since, in the year 1842, an unknown physician in a Swabian 
country town, Dr. Mayer, of Heilbronn, pointed out that a ham- 
mer 424 kilogrammes in weight, which falls from the height of 
a metre on an anvil, raises the heat of the latter by one degree 
centigrade EIA ale: ; ~ 
Leaving historical accuracy out of the question, this is a gross 
misstatement of the physical fact. The correct statement is that 
the whole heat generated by the blow (which will be partly 
taken up by the hammer and partly by the anvil) will be as 
much as would heat a Ac/ogvam of water one degree centigrade. 
Malone Road, Belfast, Dec, 28 J. D. EVERETT 
[Dr. Cohn’s words are :—‘‘ Seit im Jahre’ 1842, ein unbekann- 
ter Arzt in einer schwabischen Landschaft, Dr. Mayer von Heil- 
bronn, nachgewiesen hatte, dass ein 424 Kilogramm schwerer 
Hammer, welcher einen Meter tief auf einen Ambos fallt, den 
letzteren um einen Centigrad erwarmt,” &c, Ep. ] 
Salmonide of Great Britain 
Some months ago I inquired through the columns of the Fie? 
newspaper if any sportsman, fisherman, or naturalist would oblige 
me by replying to the following queries respecting the rarer Sa/- 
monide of Great Britain. Firstly, whether Sa/mo ferox (the great 
lake trout) had ever been takenin any lake in Wales, and, secondly, 
whether any of the Gwiniad tribe (Corvegonz), such as the 
Gwiniad of Bala, the Vendace of Loch Maben, and the Powan 
of Ireland ; or any of the Chars (.Sa/mo salvelinius) have ever been 
taken in any lake which is not a g/acial /ake—that is to say, a 
lake which either lies in the tracks of an ancient glacier, or that 
is dammed up, or otherwise surrounded by moraine matter? 
The only reply with respect to the first query was from Sir 
Philip Egerton, to the purpose that he took a specimen of Salmo 
Jerox in Bala Lake in 1871, thus establishing the fact that this 
fish still lingers in North Wales. To the second question I have 
received no reply. Is it possible that I may be more fortunate 
among the many naturalists and geologists who take NATURE? 
Pendock, Tewkesbury W. S. SyMonps 
Geographical Distribution of Dipterocarpez 
Mr. BENTHAM, in his address to the Linnean Society, de- 
livered May 4, 1872, remarks in a note, *‘ Dr. Hooker has, for 
instance, remarked that no Diflerocarfee have been found east 
of Borneo ;” but that in the present state of our knowledge it is 
premature to endeavour to establish well-marked limits between 
the flora of the western and eastern portions of the Indian 
Archipelago. 
Padre Blanco (no great authority, however), describes several 
species of Difterocarpus found in the Philippine Islands, and I 
myself sent to Mr. Robert Brown seeds of two species, one of which 
in shape and size resembled the figure giyen by Lindley in his 
** Vegetable Kingdom,” in his illustration of the genus. The seeds 
of Dipterocarpus are so peculiar, that a mistake is not easily made 
in determining most of the species. From some of those found | 
(Kan. 2, 1873, 
in these islands, valuable resins are collected. The wood of the 
trees, which are very large, is also of some economic value. * 
Manila, Oct. 8 W. W. Woop 
Honest Cyclopedias 
A FEW weeks ago Mr. A. R. Wallace asked in your columns 
if there existed such a thing as a cyclopzedia which did not mis- 
lead or blind the inquirer by harassing and often useless cross 
references. As no one has yet answered Mr, Wallace’s question, 
will you permit me to direct his attention to that admirable 
work, almost equivalent in its fullness to a cyclopzdia and far 
superior-to any cyclopzedia I know in its recent and careful com- 
pilation, namely ‘‘ Brande’s Dictionary of Science,” edited by 
the Rey. G. W. Cox. Rodwell’s Dictionary is excellent, but is 
not so comprehensive as the last edition of Brande. ar eed 
‘*The Boring in Sussex” 
ON the oth inst. I was fortunate enough to find what I believe 
to be the first fossil from the Sub- Wealden boring at Netherfield, 
three or four shells of the genus Cyc/as, in dark blue shale from 
a depth of rooft. There was also a small piece of what Dr. 
Bowerbank thinks is a Paludina. 
As there are Wealden fossils, it is supposed that the borer has 
not yet got through the lower Wealden beds. 
St. Leonard’s, Dec. 17 J. E. H. Peyron 
Reflected Sunshine 
THE recollection of a letter from Prof. Tyndall’s pen, which 
appeared in NATURE some months ago, induces me to contribute 
an account of a curious sun effect recently seen from the summit 
of the Kudure Mukh, a hill nearly 6,200 ft. high. . 
The Ghauts here rise in bold scarps from the plains, large 
tracts of the latter being at this season under water, in prepara- 
tion for the last rice crop. 
Whilst resting one evening on the edge of the cliffs, I noticed 
as the sun declined that his reflection was approaching a series of 
sheets of water some six or eight miles off. Each of these pools 
cast upwards through the blue haze that overhung the plains a 
brilliant beam of light, the oblique rays from the water crossing 
those from the sun, and forming with them a chessboard pattern 
of light and shadow that was singularly beautiful. 
As the sun dipped lower and his reflection fell full on the still 
expanse of water, the scene became almost magical. There shone 
a second sun at one’s feet, its wealth of beams, undiminished in 
splendour, springing from the very bosom of the earth. ; 
It required, indeed, but little stretch of imagination to fancy 
that a real sun was glaring up through some ghastly chasm in 
our globe. This phenomenon must be of frequent occurrence in 
many parts of the world, and wherever the distance between the 
observer and the reflecting surface is sufficient to greatly reduce 
the size of known objects, with which the eye naturally compares 
the apparent diameter of the reflected sun, the spectacle must 
always be a startling one. 
Since my return from the district a friend who was camped at 
the Mukh prior to my visit there has told me that he also 
noticed the effect described above, and used to climb the hill 
every evening of his stay for the purpose of seeing it. 
Mangalore, Nov. 21 E. W. PRINGLE 
Electricity and Earthquakes 
Ir has been suggested that earthquakes may be caused by 
electrical discharges in the interior of the earth, and this may 
account for some remarkable effects of the great shocks which 
were so destructive to Manila in 1863. 
It was observed that the effects of this earthquake were dis- 
tributed in a peculiar manner over the comparatively small space 
occupied by the city and suburbs. On the banks of the river and 
canals, and through the northern quarter, great damage was done, 
while to the southward the mischief was comparatively slight. 
In parts of the town where large churches and other solidly- 
constructed edifices were ruined, other and slighter buildings 
placed near them escaped almost withoutinjury. This was par- 
ticularly noticed in the parish of Quiapo, where the church was 
* The wood of one very large species, according to Padre Blanco, was 
formerly used in building the famous Acalpulco and Manila galleons, from 
| the circumstance that, when pierced by cannon shot, it does not splinter in 
the way most other timber is found to do. 
