POCKET BOOKS.

Among the works under this denomination for 1829, we notice two, which

from their almost indispensible utility, deserve the name of _Hardy

Annuals_. The first is _Adcock's Engineers' Pocket Book_, and contains

tables of British weights and measures, multiplication and division

obtained by inspection, tables of squares and cubes and square and

cube roots, and mensuration; tables of the areas and circumferences of

circles, &c.; the mechanical powers, animal strength, mills and

steam-engines, treatises on hydraulics, pneumatics, heat, &c., and on

the strength and heat of materials. To these are superadded the usual

contents 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

cocoa-nut, but the core was filled with the milk of human

kindness.--_Quarterly Review._

* * * * *

The Mirror of Literature, Amusement, and Instruction. Volume 13, No. 355, February 7, 1829 · 第 22 / 41 题