ON THE MEASUREMENT OF SHIPS FOR TONNAGE. 85 
government with the means of ascertaining the weight of cargo carried or 
the capacity for light goods. 
All measurements, however made, ought to be attested by the builder*or 
owner, &c. and recorded on the certificate. 
The correctness of Sterling’s rule is entirely based on the assumption 
that the sections should be measured at exactly equal distances, but experi- 
ence proves that in practice it is almost impossible to obtain these measure- 
ments at the exact intervals required. 
It is, however, of comparatively little importance by what method a vessel 
is measured, provided means are at the same time used to check the calcu- 
lations, and the most simple and practical mode of accomplishing this is by 
the method so long used by Mr. James Peake, viz. by a system of vertical 
sections and curves of areas, measured by a series of triangles. Annexed is 
a comparison of four modes of measurement. (Appendix C.) 
The black lines on the right side show the plan as recommended by the 
Tonnage Commission of 1849, and the measurement proposed in Bill of 
1850. 
The triangular lines on the extreme right represent Mr. Peake’s method 
for displacement to load-line. 
The dotted lines on the left represent Mr. Moorsom’s mode, adopted in 
the present act, as shown in formula No. 1, p. 30, in substitution of that 
recommended by the Tonnage Commission, of which he was secretary. 
The diagonal lines on the left represent M. Norman’s on the French 
plan, useful in correcting other measurements, or if built true to design. 
For statistical purposes, owing to the great decrease, as above shown, of 
from 8 to 10 per cent. in the Register Tonnage, below the average of the 
same vessel under the late law, this must impair the object of statistical 
returns, and injure the harbours, piers, and docks, maintained for shipping, 
while it reduces the charges and light dues only, and is consequently very 
opular with shipowners. 
‘Two years’ experience in the practical working of the present tonnage 
measurement and registration system, has proved deficient and non-effective 
for the attainment of most of the objects of public utility sought for. : 
The advantages of internal over external measurement have been stated to 
be, that inasmuch as the greatest number of cargoes carried by our mer- 
chant-shipping consist of stowage goods, not dead weight, equal to at least 
three-fourths of the whole, and as ships’ sides and bottoms are of various 
scantlings and thickness, and are constructed of materials of different weight, 
external measurement would give advantage to some ships over others, of 
15 to 20 per cent. 
This is, however, not the fact, as an examination into the trade returns of 
1850 exhibits the following results of the trade of the United Kingdom, 
amounting to 10,760,297 tons of imports and exports; of which 7,483,214 
tons, or 693 per cent. were of heavy goods (coal, metal, grain, and sugar), 
and 3,277,083 or 304 per cent. of light goods, of which a timber-built ship 
will carry 10 per cent. less than iron vessels. 
With respect to the working of the Act of 1854, it appears that in Sep- 
tember 1855, a great many vessels were remeasured under the new act, it 
being found that the Rule No.1 for internal measurement reduces the register 
tonnage from 5 to 10 per cent., an important saving of dock and light dues 
to coasting steamers, besides some increase in the deduction for engine-room; 
while by Rule No. 2, for external girthing, the gross tonnage was increased 
_ 5 per cent. on the late measurement, and ranged from 5 to 15 per cent. more 
than by Rule No. 1. 
