506 
Monpay, May 11th, 1857. 
JAMES HENTHORN TODD, D.D., Presinen7, 
in the Chair. 
James AntHoNy Lawson, Q.C., was elected a Member of 
the Academy. 
Professor Hennessy read a paper on the Distribution of 
Heat over the island of Great Britain. 
The President read the following note :— 
‘Sir William Rowan Hamilton wished to hand in a me- 
morandum of the following ‘General Expression by Quater- 
nions, for Cones of the Third Order,’ which he hoped to be 
allowed to develope and illustrate at some subsequent meet- 
ing of the Academy during the present Session. The equa- 
tion in question is, 
Sqpq'q'p = 05 (A) 
where p is the variable vector (or side) of the cone of the third 
order, drawn from its vertex as the origin; while g, q’, q’, are 
three arbitrary but constant quaternions, which may be re- 
garded as fixed parameters of the surface.” 
The following Memorial to Lord Palmerston was read :— 
“ To the Right Honourable Lord Palmerston, &c., &c. 
«¢ May IT PLEASE your LorpDsuHIP, 
«© We, the President and Members of the Royal Irish 
Academy, beg leave to address you on a subject of great sci- 
entific interest and importance. 
‘We have learned with much regret that the Lords of 
the Admiralty have decided upon abandoning all further 
