570
MOLESWORTH’S POCKET-BOOK
Tonnage of Vessels—continued.
tiply these three measurements together, and
divido the product by 92’4; the quotient will bo
the number of tons to be added to the result as
above ascertained.
For Open Vessels. — The depths are to bo
taken from the upper edge of the upper strake.
For Steam Vessels.—The tonnage due to tho
engine-room ia deducted from the total tonnage
computed by the above rule. To determine this,
measure the inside of the engine-room from the
foremost to the aftermost bulkhead; then mul-
tiply this length by the amidship depth of tho
vessel, and the product by the inside amidship
breadth at "4 of the depth from the deck, and
divide the final product by 92'4.
Tonnage of Vessels (Builders’ Measurement).
L — Length of keel between perpendiculars iu ft.
B = Breadth of vessel iu feet.
Tonnage - i-------^7--------— •
The fore-perpendicular is taken at the fore-part
of the stem at the height of the upper deck.
The aft-perpendicular is taken at the back of
the stern-post at the height of the upper deck.
The middle deck is taken iu three-deckers
instead of the upper deck.
The breadth is taken as the extreme breadth
at the height of the wales, subtracting the dif-
ference between the thickness of the walea and
tho bottom plank. Deductions to be made for the
rake of the stem and stern.