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65 
Catalogue. But several very successful experiments have been 
made on the possibility of applying the newly discovered photogra- 
phic processes to the object of the Pictorial Catalogue. The result 
of these experiments, which have been conducted by Dr. Graves and 
‘Mr. Tennison, has been laid before the Council, and has been so 
satisfactory, that a photographic apparatus has been purchased, and 
there is no doubt that we shall be able, at a very trifling cost, to 
produce pictures of our Antiquities, which we may communicate to 
all foreign and sister Societies, and which will be of the utmost 
value in disseminating, amongst antiquarians of other countries, 
a knowledge of the contents of the Museum. 
Notwithstanding the disadvantages under which the Academy 
has laboured during the past year, from the unfinished state of our 
premises, and from the consequent inaccessibility of our Library 
and Museum, we have had many very valuable contributions to our 
Transactions and Proceedings, in all the departments to which our 
studies are devoted. 
In Pure Mathematics, we have had papers from Dr. Graves, on 
his “ Theory of Triplets,” and on ‘‘ The Solution of Linear Differen- 
tial Equations ;” and from Mr. Jellett on “‘ The Properties of In- 
extensible Surfaces.” 
In the Mixed Mathematical Sciences, Dr. Lloyd has contributed 
to our memoirs papers on “ The Influence of the Moon on the 
Movements of a freely suspended Magnetic Needle,” and on “ The 
Meteorology of Ireland, as deduced from the Observations made 
under the superintendence of the Committee of Science.” Professor 
Allman, of Galway, has given us an account of the late ever-to-be- 
lamented Professor Mac Cullagh’s ‘‘ Lectures on Attractions and on 
Clairaut’s Theorem ;” and Mr Haughton has communicated some 
“‘Observations on the Application of Mr. Green’s Formula to M. 
Jamin’s Experiments on Reflected Polarized Light.”? The President 
has read a paper on ‘‘ The Advantages which have recently been re- 
cognised in the Cassegranian Reflecting Telescope;” and in another 
paper has explained “ An original and entirely new Method of mea- 
suring the effective apertures of the Objectives of Microscopes.” 
Professor Callan, of Maynooth, has communicated to us the results of 
his experiments ‘‘ On the Decomposition of Water by the Galvanic 
Battery, with the view to obtain a constant and brilliant Lime Light.” 
VOL. VI. F 
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