Cuap. IV., § 4.] 
use, but the invention of Brunel was not less im- 
portant as creating an epoch in art. Not only is 
it possible to execute in a comparatively short 
time, and with a prodigious economy, objects such as 
blocks and pulleys, which are required in vast num- 
bers and precisely alike, but the nicety and accuracy 
of the manufacture is thereby increased, and owing 
to the facility with which inanimate force may be 
concentrated on machinery, works which transcend 
the power of unaided muscular labour are as surely 
and exactly executed as those of smaller dimensions. 
For example, by no enlargement of the common 
turning-lathe would it be possible to construct an 
accurately turned iron steam-cylinder 8 feet or more 
in diameter, which is yet readily executed under the 
direction of a very ordinary workman by means of 
steam power and self-acting machinery. 
MECHANICS.—BRUNEL—MR BABBAGE. 
879 
structing other machines and structures. It was, in 
fact, the necessary complement of the invention of 
the steam-engine. Watt contrived the mighty Heart 
which was to give a new impulse to social life, Bru- 
nel and others of the same stamp added limbs and 
muscles, whereby its energies were rendered tho- 
roughly practical, The sixteenth, seventeenth, and 
part of the eighteenth centuries, had given to the 
world designs for countless mechanical contrivances, 
often highly original and ingenious. But many 
were grounded on fallacies, and others belong to 
the class of elaborate trifles. At that period the 
slide-rest of the turning-lathe, the planing machine, 
and the circular saw, were practically unknown; at 
least the two former, which are incomparably the 
most important inventions of their class, and which 
belong to no certain author, having almost imper- 
ceptibly come into use—the slide-rest about the Slide-rest 
end of the last century, the planing machine as "4 plan- 
lately as about 1820. The former of these readily 49 
370, The block-machinery at Portsmouth consists of a 
(370.) ry 
The block- series of engines impelled by steam, and by means of 
machinery ; which the materials of wood and metal employed in the 
chine. 
its results, 
(871.) 
Gave an 
impulse to 
mechanics. 
(372.) 
Introduc- 
tion of me- 
chanism 
into work- 
shops. 
construction of ships’ blocks are reduced to exact forms 
in graduated sizes, and are finally put together with 
very little manual labour. These machines, with the 
exception of the turning-lathe and circular saw, were 
wholly new, and, it is stated, were devised in part by 
General Bentham, who gave to Brunel at least the 
benefit of his advice and previous experiments. In 
some of them we have the first germ of implements 
now used by every machine-maker in the kingdom; 
and the ingenuity of the movements, and the variety 
of effects produced, earned for this great invention a 
just celebrity. Such a beginning could not have 
been made without the aid of government. To con- 
struct the tools was an expensive and troublesome 
business, and to start the manufactory cost L.53,000, 
which was speedily saved by the economy of the pro- 
cess. In the course of a year 140,000 blocks of no 
less than 200 different patterns were produced, and 
the number of workmen was diminished in the pro- 
portion of about 11 to 1. As a reward, Mr Brunel 
received L.16,000, being two-thirds of the first year’s 
saving, itself a sufficient proof that he was the bona 
fide inventor of this admirable apparatus, whatever 
hints he may have received from his immediate su- 
perior. 
So successful an experiment produced ultimately, 
though with characteristic slowness, its effect on the 
mercantile world ; nearly twenty years elapsed before 
such a splendid example of ingenious economy and 
artistic precision was at all generally imitated. Yet 
before his death, Sir Mare Brunel saw the fruit of his 
ingenuity almost indefinitely multiplied in the work- 
shops of London, Manchester, Glasgow, Newcastle, 
and Birmingham, and highly appreciated if less ex- 
tensively imitated abroad. 
The more we reflect on the comparative state of the 
arts now and a century ago, the more we shall find 
reason to estimate highly the introduction of correct 
and scientific ideas of machinery and of tools for con- 
forms surfaces of revolution with geometrical accu- 
racy, the latter plane surfaces, and in either case 
the application to metals is most important. The 
circular saw and slide-rest form part of Brunel’s 
series of machines, and he afterwards constructed the 
former on a very great scale for the manufacture of 
wooden veneers. To them he added the mortising 
machine, and these, it will be seen (together with the 
planing engine), form the staple of the magnificent 
and varied apparatus with which, driven by the gi- 
gantic power of steam, our mechanical factories are 
now so generally provided. We again repeat that 
the triumphs of art in which our generation glories, 
our railroads, our locomotives, our crystal palaces, 
and our steam navies, would have been impossible 
feats but for the improvement of tools and the substi- 
tution of steam for muscular power. 
Every one is, however, aware that Brunel owed his 
reputation to other achievements as well as his im- oe 
unnel, 
provements of mechanical tools. The Thames Tun- 
nel will ever be considered as his most arduous tri- 
umph. It is a structure of exquisite firmness laid 
in a quicksand. It will endure like the cloace of 
regal Rome, when the palace and the cathedral have 
crumbled to dust. Yet here also we perceive that 
it was Brunel’s exquisite mechanical tact and. inge- 
nuity which enabled him to succeed. The problem 
of the tunnel is not one of balancing vaults ; the sta- 
tical conditions of stability are simple enough, and 
it was not in the solution of such that Brunel pecu- 
liarly excelled. The practical problem was to intro- 
duce a rigid tube of brick horizontally into the 
middle of a quaking mass of mud; and the solution 
was the invention of a tool which should enable men 
to make the excavation and to proceed with the 
building in safety. It was the shield which carried The shield. 
the tunnel under the Thames,—a moveable vertical 
frame of cast iron, provided with thirty-six cells, in 
each of which a man was placed with a pick to ex- 
