ents of a pocket book, so as to render the present volume a
desirable vade-mecum for the operative, the manufacturer, and engineer.

One of Mr. Adcock's most popular illustrations will not be
uninteresting to the reader:--

_"Force of Gunpowder."_--"If we calculate the quantity of motion
produced by gunpowder, we shall find that this agent, though extremely
convenient, is far more expensive than human labour; but the advantage
of gunpowder consists in the great rarity of the active substance; a
spring or a bow can only act with a moderate velocity on account of its
own weight; the air of the atmosphere, however compressed, could not
flow into a vacuum with a velocity so great as 1,500 feet in a second;
hydrogen gas might move more rapidly; but the elastic substance
produced by gunpowder is capable of propelling a very heavy cannon ball
with a much greater velocity."

Of an opposite character, but equally useful, and more attractive for
the general reader, is the second,--_The Spoilsman's Pocket Book_, by a
brother of the author of the preceding. Here are the usual pocket-book
contents, and the laws, &c. of British sports and pastimes--as
shooting, angling, hunting, coursing, racing, cricket, and _skating_:
from the latter we subjoin a hint for the benefit of the _Serpentine
Mercuries_; which proves the adage _ex liguo non fit Mercurius_:--

"Care should be taken that the muscular movements of the whole body
correspond with the movements of the skates, and that it be regulated
so as to be almost imperceptible to the spectators; for nothing so much
diminishes the grace and elegance of skating as sudden jerks and
exertions. The attitude of drawing the bow and arrow, whilst the skater
is forming a large circle on the outside, is very beautiful, and some
persons, in skating, excel in manual exercises and military salutes."

The whole series of pocket books by the Messrs. Adcocks, extend, we
believe, to eight, adapted for all descriptions of _industriels_, as
well as for the less occupied, who are not "the architects of their own
fortunes."

* * * * *

Dr. Parr was the last learned schoolmaster who was professedly an
amateur of the rod; and in that profession there was more of humour
and affectation than of reality, for with all his habitual affectation
and his occasional brutality, Parr was a good-natured, generous,
warm-hearted man; there was a coarse husk and a hard shell, like the
co