4. Any erection on the upper deck of vessels fitted for the shelter of deck passengers on short voyages. The exemption of this space from measurement, however, is admissible only by special directions from the Board of Trade. When claim is made by the vessel owner for exemption of these spaces, the surveyors must apply to the Board of Trade for instructions.

5. The cook house and bakeries, when fitted with ovens and used entirely for their designated purposes, and the condenser space, provided the cook house, bakeries, and condenser space are not larger than are required to shelter the cook when employed at his work and the engineer when engaged in condensing water for passengers and crew.

6. Toilets of reasonable size and number for officers and crew. In the case of passenger vessels, a toilet exempted from measurement is allowed for each 50 persons, but not more than 12 toilets are exempted.

7. The light and air and funnel spaces above the machinery compartments are exempted from measurement unless the owner of the vessel, for reasons that will be explained later, requests the inclusion of these spaces within the measurement.

8. Of the space included within hatchways, one-half of 1 per cent of the gross tonnage of the vessel exclusive of hatchways is omitted from the gross tonnage.

9. The spaces within the double bottom used for water ballast are exempted from measurement. When such spaces are used for or are available for the carriage of cargo, stores, or fuel they are measured and included in the gross tonnage.

10. The spaces between the frames or ribs of a vessel and between the floor beams are not included in the measurement. The breadth of the vessel is its width between the inner edges of its frames or between the inner faces of the inner side plating. The depth of a vessel is measured upward from the upper side of the floor timber or beam "at the inside of the limber strake"; that is, next to the keelson at the center line of the vessel.

11. Companionways are exempted from measurement excepting such portions of them as are used for smoking rooms. Ladders and stairways in exempted spaces are excluded from measurement.

12. Domes and skylights are exempted from measurement.

The "certificate of survey" issued by the surveyors of the Board of Trade to vessels measured under the British rules is presented, reduced in size, in Form 1. It summarizes the spaces included within gross tonnage. The "tonnage formula," Form 2, used for calculating the ship's tonnage under the Merchant Shipping Acts of 1894 to 1907 indicates in detail the spaces that are measured. This "tonnage formula" also contains other entries that will later be considered in the discussion of net tonnage.

Number of decks..
Number of masts..
Rigged...
Stern.

Build

Galleries.
Head.

Framework and de

scription of vessel. Number of bulkheads. Number of water ballast tanks and their capacity in tons.....

Length from fore part of stem under the bowsprit
to the aft side of the head of the sternpost....
Length at quarter of depth from top of weather
deck at side amidships to bottom of keel..
Main breadth to outside of plank...
Depth in hold from tonnage deck to ceiling at
midships..

Depth in hold from upper deck to ceiling at mid-
ships in the case of three decks and upwards...
Depth from top of beam amidships to top of keel..
Depth from top of deck at side amidships to bot-
tom of keel..

Round of beam.

Length of engine room (if any).

PARTICULARS OF DISPLACEMENT.

Total to quarter the depth from
weather deck at side amidships to
bottom of keel.....

NOTE.

No. of
tons.

DEDUCTION ALLOWED.

On account of space required for propelling
power..

On account of spaces occupied by seamen or
apprentices, and appropriated to their use,
and kept free from goods or stores of every
kind, not being the personal property of the

crew.

These spaces are the following, viz:

Deductions under sec. 79 of the Merchant
Shipping Act, 1894, as follows:

Cubic meters.

Total..

No. of tons.

The only spaces above the upper deck not included in the cubical contents forming the ship's registered tonnage are...

I, the undersigned.
having surveyed the above-named ship, hereby certify
that the above particulars are true, and that her name is marked on each of her bows, and her name
and the port of registry are properly marked on a conspicuous part of her stern, a scale of feet marked
on each side of her stem and of her stern post, and lines permanently and conspicuously marked on
each side amidships indicating the position of each deck which is above water, in manner directed by
the Merchant Shipping Act, 1894.
day of

e-room measurements and the calculations for the allowance for propelling power are to be given in detail below.

SUEZ GROSS TONNAGE RULES.1

The Suez Canal Co.'s rules for the measurement of vessels, as has been stated, were formulated by the International Tonnage Commission at Constantinople in 1873. That commission adopted the Moorsom system of measuring vessel spaces, and the rules of the commission state that there shall be included within the gross tonnage "all spaces, without any exception, below the upper deck," and "all permanently covered and closed-in spaces on that deck."

In measuring the superstructures upon or above the uppermost full-length deck, the rules as amended in 1904 provide for the exemption from measurement of portions of certain closedin spaces which are considered as open under the rules of the country of the ship's registry. The provisions of the rules are as follows:

I. SHIPS WITH ONE TIER OF SUPERSTRUCTURES ONLY.

1. Poop, bridge, forecastle. The following exemptions are allowed:

(a) Such length of the poop measured from the inside of the stern timber, at half height of the said poop, as shall be equal to one-tenth of the full length of the ship.

(b) The portion of the bridge in way of the air spaces of [spaces within and at the side of casings above] the engine and boiler spaces, it being understood that such air spaces are not considered to extend beyond the forward bulkhead of the stokehold and the after bulkhead of the main engine room. [See figures accompanying Appendix XIII.]

(c) Such length of the forecastle measured from the inside of the stem at half height of the said forecastle as shall be equal to one-eighth of the full length of the ship.

(d) In each of the above three cases of superstructures such portions in the walls of the ships as are in way of openings not provided with any means of closing and corresponding to one another.

2. Poop and bridge combined, or forecastle and bridge combined.-In each of these combined spaces the following exemptions are allowed:

(a) That length only which corresponds to the openings of the engine room and boiler spaces as specified in (b) above.

(b) Such portions as are in way of openings not provided with any means of closing and corresponding to one another.

3. Shelter decks. In the case of shelter decks the following exemptions are allowed: The portions in way of openings in the side plating of the ship not provided with any means of closing and corresponding to one another. Such air spaces as are situated within the shelter deck must be measured into the engine-room space and deducted, together with 75 per cent of their volume.

II. SHIPS HAVING MORE THAN ONE TIER OF SUPERSTRUCTURES.

(a) The exemptions prescribed in paragraphs 1, 2, and 3 above are applicable in their entirety to the lower tier only.

(b) Tiers above the lower tier are only allowed the exemption of such portions as are in way of openings in the side plating of the ship not provided with any means of closing and corresponding to one another.

The foregoing rules stipulate that when a vessel has one tier of superstructures, including detached poop, bridge, and forecastle, there shall be exempted from measurement and gross tonnage, when the spaces are considered as closed-in by the Suez rules and as open by the rules of the country of the ship's registry: (a) The space included in the poop for a distance of one-tenth of the length of the ship measured from the inside of the stern timber; (b) the portion of the bridge or the combined poop and bridge within and at the side of, and for the length of, the casings surrounding the air spaces above the engine and boiler room; (c) the space included in the forecastle for a distance equal to one-eighth of the length of the ship measured from the inside of the stem; and (d) in the case of all three of these superstructures, the space between opposite permanent openings in the side walls of the ship.

1 See Appendixes XII and XIII for the Suez Canal Co.'s rules for the measurement of vessels and for the "memorandum" concerning the application of the rules to the measurement of superstructures.