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.

When the poop and bridge are united into a continuous structure, the space within the poop equal to one-tenth of the length of the ship is not exempted from measurement. Likewise, when the forecastle and bridge are combined there is no exemption of the space within the forecastle equal to one-eighth of the length of the ship; but that portion of the bridge taken up by the light and air space above the engine and boiler room is exempted from measurement, as are also spaces between permanent opposite openings in the side walls of the ship. The memorandum issued by the Suez Maritime Canal Co. upon the application of its 1904 rules to the measurement of superstructures states that when the poop, bridge, and forecastle are united into one they constitute a shelter deck. In the case of the shelter deck thus formed, the only spaces exempted from measurement are "the portions in way of openings in the side plating of the ship not provided with any means of closing and corresponding to each other," and the rules further provide that "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." When a vessel has two or more tiers of superstructures, the foregoing exemptions regarding the spaces within the poop, bridge, and forecastle, when separated from each other and when combined, apply in their entirety only to the first tier of superstructures above the upper fulllength deck of the ship. As the rules above quoted state, the tiers above the lower tier are allowed the exemption of only such spaces as are between permanent opposite openings in the sides of the ship.

Steamers now in service may have numerous superstructures, such as roundhouses, side houses, galleys, cookhouses, bathrooms, wheel, chart and donkey-engine houses, and inclosures required for the working of the ship, for smoking rooms, and companion houses. All such spaces are measured and included in the vessel's gross tonnage. Hatches, also, as has been stated, are measured and their space in excess of one-half of 1 per cent of the gross tonnage of the vessel exclusive of hatchways is included in the ship's tonnage.

The definitions given to closed-in and open spaces by the rules of the Suez Canal Co. are stated on page 47. These definitions, formulated by the International Tonnage Commission upon the recommendation of the representatives of Great Britain, provide that all spaces capable of being so closed as to be usable "for the stowage of merchandise or for the berthing and accommodation of the passengers or of the officers and crew" shall be included in the measurement, and that openings in the deck or coverings of the spaces or in the partitions separating the spaces under the deck containing the openings shall not entitle spaces to exemption from measurement if the openings can be so closed, after the ship has been measured, as to make the spaces available for the transportation of goods or passengers. In order to make this rule effective and to avoid the attempts that had been made to exempt shelterdeck spaces from measurement,' the Suez Canal Co. in 1902 adopted the rule still in force that "should a vessel at any time transit with merchandise of any kind, or bunker coal, or stores of any description, in any portion whatever of any exempted space, the whole of that space is added to the net tonnage and can nevermore be exempted from measurement." The enforcement of this principle has resulted in including in the gross tonnage of the vessels measured under the Suez rules their usable or earning capacity. Moreover, the determination of what is an open or a closed space does not rest with the measurers of vessels but with the officials of the canal company charged with the duty of collecting tolls and hence with checking up the tonnage of vessels.

Briefly stated, the Suez rules as now enforced so measure the gross tonnage of vessels as to include in that tonnage the entire space (with the exception of designated exemptions enumerated below) under the tonnage deck and between the tonnage deck and the uppermost deck and the space (subject to the exemptions allowed some ships by the "memorandum" of 1904) in such superstructures as poop, forecastle, bridge, side and round houses, galleys, and bakeries. The term "permanent closed-in" is defined to mean spaces so fitted as to be capable of being so closed as to be used for the transportation of cargo, fuel, provisions, or passengers.

1 For an historical account of the treatment of the measurement of superstructures by the Suez Canal Co. consult Appendix XI.