A

TREATISE

OF

MECHANICS,

THEORETICAL, PRACTICAL,

AND

DESCRIPTIVE.

BY OLINTHUS GREGORY, LL.D.

OF THE ROYAL MILITARY ACADEMY, WOOLWICH;

HONORARY MEMBER OF THE PHILOSOPHICAL SOCIETIES OF LONDON AND

NEWCASTLE-UPON-TYNE,

AND OF THE NEWCASTLE ANTIQUARIAN SOCIETY.

THE THIRD EDITION,

CORRECTED AND IMPROVED.

VOL. II,

CONTAINING

REMARKS ON THE NATURE, CONSTRUCTION, AND SIMPLIFICA-
TION OF MACHINERY, ON FRICTION, RIGIDITY OF CORDS,
FIRST MOVERS, &c.

AND

DESCRIPTIONS OF MANY CURIOUS AND USEFUL MACHINES.

-Talem intelligo Philosophiam naturalem, quæ non abeat in fumos
speculationum subtilium, aut sublimium; sed que efficaciter operetut,
ad sublevandi vitæ humanæ incommoda. BACON. De Aug. Sci.

LONDON:

PRINTED FOR F. C. AND J. RIVINGTON; G. WILKIE; J. RICHARD-
SON; LACKINGTON AND CO.; LONGMAN, HURST, REES, ORME,
AND BROWN; J. TAYLOR; BALDWIN, CRADOCK, AND JOY;
WALKER AND EDWARDS; AND JAMES HARPER AND CO.

6

1815.