41 
little way into a small bottle containing a small quantity of 
sulphuric acid, prevents the access of moist air into the 
short limb. 
The tube thus completed possesses the following advan- 
tages : — 1st. There is the utmost facility in the movement 
of the column, so that the most minute changes of pressure 
are at once registered without any dragging. 2nd. The 
depression produced by capillary action is reduced to one 
half, so that the siphon arrangement can be satisfactorily 
used as affording an accurate neutralization of capillary 
action. 
Mr. Brothers exhibited the plates forming the first part 
of the Holborn Society’s photolith reproduction of Hans 
Burgman’s Triumphs of Maximilian I. The designs are 
engraved on wood and printed on separate sheets, but the 
set shown were mounted so as to exhibit the artist’s inten- 
tion — that of a triumphal procession. This remarkable 
work is considered to be one of the finest specimens of 
wood engraving. 
Mr. Baxendell read the following letter from Professor 
C. PiAzzi Smvth, F.R.S., Astronomer Royal of Scotland : — 
Referring (as the prompt and frequent publications of your 
Society so easily and agreeably enable one to do) to Professor 
Osborne Reynolds’s triumphant proof, on November 18th, 
that his glass tubes were strong enough to act as guns, — and 
also that 1 *5 inches depth of powder produced nothing like 
the force exerted by the electrical discharge; and that that 
electrical discharge acted by means of conversion of water 
suddenly into steam, as when lightning rends a tree; — 
may I beg to offer two remarks ? 
(1) The soundness of the discussions before the Society 
on the recent wood-struck case near Manchester, is evident 
by a similar conclusion arrived at by the British Associa- 
