ON SHIPPING STATISTICS. 243 
increase; and as it is to be expected that mercantile competition will always 
cause the cost of freight on the general aggregate of the trade of the country 
to be proportionally ruled by the prime-cost expenses that may be actually 
incurred in doing the work, it appears manifest that the public economy de- 
pendent on the general realization of shipping improvement is a considera- 
tion that involves public interest to the extent of millions sterling per 
annum. 
To demonstrate the vast importance of this subject, Appendix No. 2 has 
been compiled from the returns of the Board of Trade, to show the amount 
of trade between the United Kingdom and foreign countries during the year 
1855. This compilation shows that the tons weight of cargo actually carried 
in the foreign trade of the United Kingdom in the year 1855 amounted to— 
Taipotts . 3.4... 6,254,259 tons. 
WESUGTGS po ots ues 8,370,363 tons. 
Total .... 14,624,622 tons. 
Nearly 15 millions of tons weight of sea-borne cargo, conveyed at probably 
25 per cent. extra cost beyond what would be incurred if ships of the high 
order of dynamic merit exemplified by the Bremen were only and exclusively 
employed. 
By aid of Appendix No. 2, showing the amount of trade between Great 
Britain and all foreigu countries respectively, parties conversant with shipping 
affairs will be enabled to estimate approximately the gross amount annually 
involyed in the goods-transport service of Britain. ‘Thus public interests 
require that the statistical records of shipping should embrace such data as 
will be availably conducive to shipping improvement, by affording the means 
of approximately estimating the dynamic capabilities of ships, whereby every 
ship constructor and ship owner, and the directors of steam-shipping compa- 
nies, may be enabled to test the dynamic merits and condition of their ships 
respectively,—a system, which would gradually lead to the adoption of such 
types only as develope a high order of dynamic duty, and would obyiate some 
of the most serious hazards to which private and public interests are now 
exposed from vessels being employed on commercial and postal services for 
which they are not fit. 
Ouly let it be publicly known, as exemplified by the Bremen, that steam- 
ships and their machinery may be so constructed, that on being subjected to 
a test-trial, the cube of the speed in knots, multiplied by the square of the 
cube root of the displacement, and divided by the indicated horse power, 
ought, in the present day, irrespective of future improvement, to produce a 
quotient or coefficient of dynamic duty equal to the number 319, and that 
the coefficient deduced from the rule thus enunciated constitutes (ceteris 
paribus) a criterion of the cost price at which steam-ships perform their work ; 
and we shall then soon find that this test of dynamic merit, or the numeral 
coefficient deduced therefrom, will enter into the calculation of the pecuniary 
value of steamers to such extent that ships of a low order of dynamic capa- 
bility will not be built, because they will not sell. 
~The test of dynamic merit, as above set forth, based on the mutual rela- 
tions of displacement, speed, and power, presumes on the net power effect- 
ively applied in propelling the ship being always in a constant and known 
ratio to the gross indicated power. 
The inquiry, therefore, so far, is of such a nature as demands professional 
knowledge and skill in order to determine and discriminate between the merit 
‘that may be due respectively to the type of form of the hull, and to the con- 
