114 _ REPORT—1857. 
ing (that is, within the limitations of the variations of build referred to -in 
Tables A and B), through the intermediate element “displacement,” the two 
Tables A and B thus establishing the mutual relations within the limits afore- 
said, between builders’ tonnage, gross register tonnage, and weight or cargo 
tonnage, with the power required to attain a given speed, thus enabling us 
to show the bearing of proportions of build as affecting mercantile steam 
transport economy. 
In the first place, therefore, before entering on this exposition, and in con- 
sideration that persons generally, even amongst those who devote their time 
to popular and statistical studies, and to scientific pursuits, and even assume 
the responsibilities of legislation on shipping, are not familiar with the technical 
meaning of the terms “tonnage” and “burden,” which are of such frequent 
recurrence in discussing the properties of shipping, as compared with the 
ordinary and unsophisticated meaning of those words, and are actually and 
unconsciously misled by those terms, when used technically in shipping so- 
phistry, having a signification quite at variance with their ordinary meaning, 
{ will endeavour to dispel this mystery by a few remarks in explanation of 
the terms “tonnage” and “ burden,” which, above all other terms, are most 
amenable to the foregoing singular imputation, namely, that their technical 
meaning is directly at variance with the ordinary signification of the said 
words: for example, ship's “tonnage” is not spelt with a u, “ tunnage,” and 
we all know that a “ton,” as distinguished from “ tun,” popularly signifies 
2240 Ibs. weight, or 20 ewt., each ewt. being 112lbs. The ordinary accep- 
tation of the word “ton” implies a unit of weight, not of measure. Thence 
it is popularly inferred that the “‘tonnage” of a ship means the number of 
tons weight which constitute the proper load of a ship; but what is a ship’s 
tonnage as implied in the terms “ tonnage O.M.,” “tons burden,” “ register 
tonnage”? It has nothing whatever to do with weight. By the old law, termed 
builders’ measurement O.M.,” which, though legally superseded in 1835, is 
still practically in use, and constitutes to this day the rule which, even in 
the Government service, generally regulates the builder's contract price of 
shipping, the measurement of this tonnage is regulated by the length of the 
ship and its breadth only, taking no cognizance of depth. It has nothing 
whatever to do with the load-draught of water for which a ship may be 
constructed. Provided that the length and breadth of two ships be the 
same, the builders’ tonnage O.M. will be the same, though the load-draught 
of one ship be 30 feet and of the other only 3. This same tonnage, builders’ 
measure O.M., is also frequently called by the equally delusive term “burden,” 
though, as above shown, it has nothing to do with burden; for example, in 
shipping advertisements we see daily that “tons burden” is a designation by 
which ships are commonly advertised. It is true that Parliament abolished 
that law of tonnage, builders’ measurement O.M., or the so-called ‘ burden,” 
in 1835, but nevertheless the Government have continued to uphold the 
rule (builders’ measurement) as the base of their ship-building contracts, and 
ships, as respects their comparative size, are still only known to the world 
generally by their so-called tonnage or tons burden, or builders’ measure- 
ment O.M. No steps having been taken by the Government to discontinue 
and forbid the use and adoption of the old law of measurement, though 
repudiated by statute in 1835, it has continued to prevail, and merchants, 
following the example of the Government, make it the general base of build- 
ing contracts to the present day. 
It is therefore submitted for the consideration of the British Association, 
that the statute abolition of tonnage builders’ measurement O.M., also called ' 
“burden,” ought not to be permitted to lie dormant. It should be expressly 
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