ON THE MEASUREMENT OF SHIPS FOR TONNAGE, 75 
nage or roomage, or whatever it may be called, employed for mercantile 
purposes. The space available at the usual rate of 40 cubic feet to a ton, is 
quite sufficient for the purpose ; and as the internal roomage divided by 100 
does on the average bear a definite ratio to this space, I am inclined to think 
that the present registration is sufficient for merely statistical objects. 
Among the reasons which have weighed most with me, in arriving at the 
above conclusions, are the following :— 
In all the rules which have been established by Act of Parliament for the 
measurement of tonnage, the legislature has had one object in view, viz. to 
provide for the fair incidence of tolls. 
If measurement by weight were taken as the basis of registration, external 
measurement, as proposed by the Tonnage Committee of 1849, viz. up to 
the deck, would not be more correct than the present legalized internal 
measurement; and it would have the disadvantage of offering an induce- 
ment to build ships of insufficient strength—as the greater the ratio of the 
internal to the external capacity for the greater number of cargoes, the more 
advantageous would the arrangement be to the owner. It is generally 
acknowledged that a comparatively large interior space or roomage, is-of prin- 
cipal importance in the eyes of shipowners; and that it would not be a recom- 
mendation generally, that, with a small internal capacity, a vessel possessed 
- large capacity for carrying weight. If, therefore, the registration were based 
on external measurement, it would become the interest of the owner to 
reduce the scantling of the vessel to the lowest possible dimensions—even 
verging upon danger. 
The ‘ Great Eastern,’ now building at Millwall, will have a large external 
- displacement compared with its internal roomage, owing to its being built on 
the cellular principle. I cannot think this an advantage, viewed merely in a 
commercial or economical point of view, as the prime cost is greater, and the 
vessel when built is not as available for the ordinary run of merchandise as 
others which have a proportionably larger internal roomage. 
The strength of a vessel is a very important element in its construction ; 
and it appears to me that the registration of tonnage for dues on the external 
instead of the internal measurement up to the deck would operate greatly to 
the detriment of this element. 
The carriage of passengers cannot be considered as among the least 
luerative of the uses to which a ship may be put. The room required for 
each passenger is out of all proportion greater than the weight of himself 
and luggage. Passenger ships, with a comparatively small displacement, 
require large internal roomage; and as all covered spaces are included in the 
present internal measurement, the incidence of dues is far more just on the 
present law than it would be on a law which established a system of mere 
external measurement. 
It has been urged that the prevalence of shipwrecks and consequent loss 
of life must be laid to the door of the present defective state of shipping 
registration. I do not, however, find that the result of the inquiries of per- 
sons most competent to judge corroborates this view. Among the causes 
which the seamen themselves (no incompetent judges) urge, such as the 
enormous competition of late years, insufficiency and incompetency of crews 
and officers, I do not find the overloading of ships. I cannot but infer from 
this significant silence that such a cause is not in operation, at least to any 
considerable extent. 
To appreciate the qualities of a vessel in a scientific point of view, a know- 
ledge of the light and load displacements, as well as of the area of midship 
section, and of the form of the ship, especially towards the bows and stern, 
