Correspondence—Prof. T. G. Bonney. — 189 
the evidence for his deductions was discussed, it being thought 
improbable that these would be at once or entirely accepted. ‘The 
expanding field of geological investigation as the science progressed, 
was alluded to, fresh and important discoveries ever rewarding those 
who laboured to complete the history of the earth. 
A vote of thanks for the Address was proposed by Dr. Hull and 
seconded by the Rev. Dr. Haughton, who observed that for thirty 
years he had taught the geology of the past, and now contemplating 
the geology of the present, he shrunk from conjecturing what might 
be that of the future. He was glad to find the discoveries of the 
late Prof. Tresca, of Turin, as to viscous fluidity from pressure, 
occurring in the case of solids and metals like silver, lead and gold, 
applied in explanation of geological structure. Andin this connexion 
he was reminded of the deposit of gypsum cut through in forming 
the St. Gothard tunnel, which under great pressure flowed into the 
tunnel and stopped the works. The Carboniferous Ice-age possessed 
considerable interest to him from his having been the first to record 
glacial boulders of that period. He was much pleased with the 
Address and felicitated the Society upon the election which had 
taken place. 
CORRESPONDENCE. 
ee 
DYKE IN THE LIZARD SERPENTINE! 
Srtr,—In reference to Mr. Somervail’s answer (last month) to my 
letter indicating two inaccuracies in his article on a dyke in the 
Lizard Serpentine, permit me to state that I did not mistake the 
south for the north end of Pentreath Beach, or the locality of which 
he wrote. Jt is not my custom to criticise without using all pains 
to ascertain what an author has said or (if possible) what he means. 
As to this dyke, I believe (though to be quite sure I should have to 
revisit the locality) that in my diary I have a sketch of and a note 
on part of it; but at any rate I know its situation. On the theo- 
retical and hypothetical views put forward in the article and the 
letter I do not presume to comment. Mr. Somervail has doubtless 
discovered some quicker and surer way to a conclusion than the 
laborious route on which I have been obliged to plod. 
23, Duennine Roap, Hampsteap, N.W., T. G. Bonney. 
February 2, 1889. 
SCIENTIFIC BIBLIOGRAPHY .! 
Stzr,—All workers will most cordially endorse the remarks of Mr. 
S. 8. Buckman (Gnon. Mac. N.S. Dec. III. Vol. VI. No. IL. p. 94. 
London, Feb. 1889). But surely the Societies are not to blame for 
sins of omission in “ Authors’ Copies.” It is always open to the 
author of a paper, when ordering his separate copies, to order at the 
same time a title-page or printed cover which shall give all necessary 
details. It is not to the advantage of a Society to permit an author 
to issue his paper as though it were an independent publication : 
' The Editor regrets that Prof. Bonney’s and Mr. Bather’s letters were omitted 
from the last number of the Magazine from want of space. — Epir. G.M. 
