PREFACE.
Sectional Dry Dock, Philadelphia , and the Floating Balance Dry Dock, Portsmouth,fully illustrated by engravings on steel.
Care has been taken to refer constantly to the official records of the Navy De partment , and the reports of the engineers in charge of the several docks duringtheir construction, for valuable and reliable information.
It is believed that this work will be found interesting to the American statesman,and the officers of the Government, particularly those of the Army and Navy ; andto the engineers, mechanics, and contractors of the country, the mass of statisticalinformation it contains, including the detailed cost of the particular works described,cannot fail to be eminently useful
CHARLES B. STUART.