268 NOTICES OF THE MEETINGS [March 4, 
Let us see what would be the result of the substitution of the 
steam plough for our present systems of ploughing. In England, 
taking Caird’s estimate, there are 14,000,000 acres in tillage ; these 
are ploughed certainly once every year. The cost of the operation 
averages at least ten shillings per acre—thus giving a total of 
£7,000,000, per annum. This first machine of Usher does the 
work better than by the plough, for two and sixpence per acre, 
or at seventy-five per cent. less cost. The saving would consequently 
be about £5,250,000 per annum. The labour of 50,000 men and 
100,000 horses required for this one operation would be replaced, 
and a saving in the consumption of corn effected, to at least 
1,500,000 quarters, which would be thus rendered available for the 
more direct wants of the community. 
(I. W.] 
WEEKLY EVENING MEETING, 
Friday, March 4, 
Tue Duxx or NortTHUMBERLAND, K.G., F.R.S., President, 
in the Chair. 
Epwarp A. Freeman, Esqa., M.A. 
On the Constructive Principles of the Principal Styles of Architecture. 
Tue Lecturer stated his object to be to trace out the essential 
character of the principal styles of architecture as directly derived 
from their constructive principles, with as little reference as pos- 
sible either to mere ornamental detail, or to the outlines and 
ground-plans of buildings. The latter are closely connected with 
the question of actual style; they modify it and they are modified 
by it; but they are directly derived from considerations of habit, 
convenience, or religion, rather than from the real constructive 
origin and principle of the style itself. 
The constructive origin of each primitive and unborrowed style is 
generalty to be looked for in the sort of primitive habitation which 
each nation seems to have imitated in its first architectural works, 
that namely with which each had been most familiar in its pri- 
mitive and uncivilized state. This subject has been worked out 
in the well-known Essay of Mr, Hope, and more recently treated 
of by the Lecturer himself in his History of Architecture. The 
Egyptian architecture reproduced the primitive excavation, the 
Grecian the primitive hut, the Chinese the primitive tent; each 
presenting a stove imitation of the earlier and ruder fabric. 
