ON THE MEASUREMENT OF SHIPS FOR TONNAGE. 95 
Thus, the portion of these exports sent to countries using the metrical 
ton amounts to above £28,000,000. A considerable proportion of the 
countries to which the remaining £68,000,000 of goods were exported 
does not use either the English or the metrical ton, but some other weight. 
So large a proportion of our foreign commerce being already carried on with 
nations using the metrical ton, it appears highly probable that the adoption by 
Great Britain of the metrical ton as the unit of weight tonnage, would speedily 
lead to its universal adoption throughout the world. Nor can it be questioned, 
that this would be a most proper adjunct to the recent alteration of the Navi- 
gation Law, by which the ships of all countries are permitted to carry goods 
and passengers to and from Great Britain with unrestricted freedom. A 
common method of computing the carrying powers of ships, would be a 
manifest and indisputable advantage. For statistical information, the adop- 
tion of the metrical ton weight is indispensable. At two great statistical 
congresses, Brussels, 1853, and Paris, 1555, it was recommended that the 
weights and measures of the Metrical System should be universally employed 
as common terms of comparison, reference being made more especially to the 
tonnage of ships*. 
Let us now consider the advantages of the metre as a linear measure, and 
of the metrical ton based upon it, independently of their extensive adoption 
throughout the world. According to the English method, the measures of 
length are generally computed in feet, inches, and eighths of an inch ; or, if 
recourse is had to decimals, as directed by the late Mercantile Shipping Act, 
in feet and hundredths of a foot. The tise of a measuring-line, divided into 
metres and centimetres, appears to present at least equal advantages, and 
would be simple, easy, and commodious in the extreme for tonnage measure- 
ments, having all the recommendations of a decimal system. 
If the metrical ton be adopted as the base of ships’ tonnage, the displace- 
ment between the light and load water-lines, expressed in cubic metres and 
centimetres, will give the metrical tonnage without any further trouble and 
with perfect exactness, because a metrical ton is the weight of a cubic metre 
of water. This remarkable facility is obtained, because in constructing the 
Metrical System, care was taken to adjust the weights so that they might 
have a direct and simple relation to the measures. In the English weights 
and measures this principle has been disregarded. 
Suppose now that we follow the new law, the Mercantile Shipping Act of 
1854, which, however, is never likely to extend itself to the world at large, 
because in this law “the ton” is a palpable misnomer, not being a weight of 
any kind, but a certain extent of internal space. Under this law the cubic 
contents of every part of a vessel, adapted to carry passengers or cargo, are 
ascertained either by Sterling’s rule or some other approved formula, and 
are expressed in cubic feet. The number of cubic feet is then divided by 
100, this number having been adopted as the divisor in order to assimilate 
the new tonnage registration to the former tonnage registration. 
If we apply the metre as the unit of linear measure, we shall find the in- 
_ ternal space in cubic metres instead of cubic feet, and we can easily reduce 
the one measure to the other, because a cubic metre being equal to 35°32 
cubic feet, the number of cubic metres multiplied by the decimal °3532, will 
give the number of tons measure at the rate of 100 cubic feet to the ton, 
according to the principle of the new law. 
__ It thus appears that the metrical ton, differing from the British weight of 
the same name only by about 15 parts in 1000, whereby a ship capable of 
___ * See Rouher and Legoyt, ‘ Compte Rendu de la Deuxiéme Session du Congrés Internas 
tionale Statistique.’ Paris, 1856, 4to., p. xv., 169-172, 192, 193, 256, 257, 
