A PRACTICAL TREATISE.

BY

JOSEPH W. ZAEHNSDORF.

WITH PLATES AND DIAGRAMS.

SECOND EDITION, REVISED AND ENLARGED.

LONDON: GEORGE BELL AND SONS,

YORK STREET, COVENT GARDEN.

1890.

CHIS­WICK PRESS:—C. WHIT­TING­HAM AND CO., TOOKS COURT, CHAN­CERY LANE.

DEDICATED TO