The Sun.
London, England, 1856-08-16 00:00:00

may exist and be destructive of enterprise which might
otherwise have conduced to public good. In short, my
object is to show that in consequence of the deficiencies in
our national standard units of power and tonnage, and de-
ficiencies of our statistical registration, the public are de-
prived of the benefits capable of being derived from
science as a means of discriminating between good and
bad practice in the great matter of shipping, thus ena-
bling us to take advantage of the one and explode the
other. The constructive merits of steam ships in a dyna-
mic point of view may be comparatively determined by
the ratio that subsists between the amount of displacement
that is propelled from place to place, the speed or time in
which the vessel performs the given passage, and the
engine-power exerted, or the coal consumed in the per-
formance of the work ; yet every ship that is launched
and goes with flying colours upon the usual test trial
is always for the day pronounced to be the most
wonderful ship that ever was built; and no wonder that it
is so, considering that the dynamic merits of ships are
thus determined, not by any admitted rule based on the
mutual relations of displacement, power, and speed, but
by acclamation based on the mutual interests of all con-
cerned, that a new ship shall be of good repute. All at-
tempts to expose this monstrous deficiency in our nautical
system by urging the importance of statistical registration,
have been held up to reprobation as an interference with
the shipping interests, regardless of the fact that it is the
public who pay the penalty of an enhanced price of goods
transport consequent on whatever deficiencies may exist
in connection with the locomotive properties of our ship-
ping. In justification of these remarks as to our denomi-
nations of ships' tonnage and engine-power being a delu•
sion, subversive of all truth, so far as scientific inquiry
and research may be based thereon, I may be permitted to
cellos) the following statements :-Ist. As to to tonnage
registration. Although tonnage measurement for regis-
tration has been subjected to legislative revision under
the Merchant Shipping Act of 1851, the term " tonnage"
is still made use of in various significations. By the pre-
sent law, 100 cubic feet of internal tonnage, or available
space for cargo, constitutes the unit of tonnage, but as
respects all ships built previously to the month of May,
1855, when this act came into operation, the adoption of
this law is not compulsory. Merchants have the privilege
of retaining the former registration of some ships, and
getting such others of their ships measured and registered
under the new act as they may think fit to select for re-
gistry, so that the term tonnage may now signify " build-
ers' tonnage," old meaeure, under the Act of 1775, or ton-
nage under the Act of 1833, or tonnage under the Act of
1854, and these are three totally different systems of ad-
measurement, having no definite ratio to each other.
Mon over, the unit of tonnage under the Act of 1854 being
based on internal room:ego measuring up to the deck, affords
no certain indication of the displacement of a ship when
loaded fit for sea, nor does it afford any assurance what-
ever as to the tons' weight of cargo that a ship will carry ;
for example, by adopting the cellular princiele of build
now introduced in the construction of iron ships, a ship
of 10,000 cubic feet of internal roomage, or 100 tons re-
gister tonnage, may have such external displacement as
would safely float with the whole internal roomage filled
with iron, and therefore weighing no less than 1,000 tons
of dead weight, or ten times the register tonnage ; and the
registration of steam ships is open to similar delusion as to
their capability for weight of cargo. So much for the mer-
cantile liberties that may possibly introduced, and taken
with our statistics of exports and imports so far as they
may be based on the tonnage registration of shipping un-
der the Act of 1854. The abortiveness for statistical and
scientific purposes which has hitherto attended all legislas
tion on tonnage registration appears to have been occa-
sioned by the attempt to embrace under the one term,
, " tonnage," two things which have no fixed ratio to each
other, namely, tonnage by bulk, and tonnage by weight.
The law has not comprehended the double mercantile use
and application of the term " ton" by providing for the
separate and distinct registration of each, namely, tonnage
by hulk and tonnage by weight—the capability of ships
for bulk tonnage being dependent on internal roomage,
but the capability of ships for weight tonnage being depen-
dent on external displacement—a distinction which is not
noticed by the new law of tonnage admensurement under
the Act of 1854. 2d. As to marine engine-power. Although
Watt originally defined the unit of power, which be de-
nominated horse-power, as equivalent to .13,0001b5. weight
raised one foot high in one minute of time, and invented
mechanical device or instrument called a " steam indica-
tor," whereby the variable pressure of the steam in the
cylinder, and consequently the working power of steam-
engines, could be readily ascertained (whence the working
power so ascertained was denominated the " indicated
horsepower"), all which arrangements of Watt put the
working operation of the steam-engine originally on a
scientific base, defined by a standard unit o power ad-
naeasurement, still this definite unit of power was never
recognised by law, and consequently the steam-engine
was no sooner applied to maritime purposes than the
rivalry of trade induced a practice under which the
nominal, or contract power of engines, did not speci-
fically regulate the working capability of the engine
delivered. Engines were not objected to by the pur-
chaser if their working capabilities were in excess of the
nominal power, and engineers themselves voluntarily sup-
plied marine engines working up to an "indicated" power
far in excess of the "nominal" power, for the express pm-
pose of thereby driving the new vessel at a higher rate of
speed than that attained by some rival vessel with the
same nominal power. Reputation for the production of
fast steamers depended on beating the rival boat, not on
the mode of effecting that object. The shipping interest
and their working craftsmen, shipwrights and engineers,
felt themselves constrained to meet their rivals in trade
with their rivals' weapons ; numerous devices have been
adopted with a view to the development of power on board
of ship by packing the greatest amount of engine-power
into the least space, and undoubtedly great improvements
have been made by adapting the dimensions and propor-
tions of vessels to the service required, but still fame,"
in regard to the character of steam=ships based on speed,
has been too much the result of horse-power delusive
jockeyship rather than of truthful science. By the practice
of trade horse-power came to be measured by the diameter
of the cylinder, without any limitation as to the capabili-
tiesof 11119 b Ater, and gradually in time a marine-engine con
tract was co Isiderecl not to be fulfilled unless the engines
were capable of working up to an " indicated horse-power,"
at least double that of the contract nominal power ; still,
however, no specific limit was assigned either by custom or
by law ; and, at length, to such a degree has competition
set truth at defiance, that the working, or "indicated
horse-power" of engines delivered under contract has fre-
quently amounted to four times the nominal horse-
power actually stipulated for by the contract. These
facts are fully set forth in the paper read by me before
the Society of Arts on the 16th May, 1855. Having thus
pointed out the indefinite application in steam shipping
practice of the terms " tonnage" and " horse-power"
with reference to the definite terms " displacement" and
" indicated horse-power," it may be still further edifying
that we illustrate the anomalies liable to result when these
terms are used in combination with each other, as is con-
stantly the case in expressing and recording the ratio of
tonnage to power of a steam-ship. In exposition of this
matter, I may again refer to the before-mentioned paper,
whereby it will be seen that I selected 10 vessels, in each of
which the ratio of builders' tonnage to nominal power was
very nearly the same, namely, in the ratio of 100 tons of
builders' tonnage to 40 nominal horsr-power, or 2e tons of
tonnage to one nominal horse-power • but on comparing
the constructors' load displacement of these same ships,
calculated in tons weight at 35 cubic feet of water to the
ton, with the effective working power, based on indicator
measurement, the ratio was found to be 10 tons displ
ice-
ment to 3e horse-power in one case, and 100 tons oispl ',ce-
ment to 281 horse-power in another. The records l sta-
tistics of these 10 vessels would lead one to infer that they
are all powered in the same proportion of engine-power to
size of ship ; but, in fact, they are all different, and on
comparing the two extremes, one ship has no less than
seven times the power of the other in proportion to size of
ship as determined by displacement. In fact, generally,
the records of register-tonnage and nominal horse-power
do not constitute statistical data of any value whatever for
the scientific purpose of discriminating between the rela-
tive dynamic merits of steam-ships, but, on the contra! v,
such records and all ideas resulting therefrom are positively
delusive and mischievous. The conclusion at which I
would arrive from these statements is, that the very first
step in any attempts to bring steam affairs within the
range of arithmetical calculation must necessarily he to
establish the measure or value which wo assign to cur
units of tonnage and po.ver. It is only by the moral in-
fluence of such a body as the British Association that the
cause of science can obtain a hearing in this matter of
statistical registration applied to shipping. With refer-
ence to or units, it is, of course, desirable that the mea-
-1 sure of the unit, to be legally recognised as the unit of
power, should be nearly in accordance with the general
average of practice at the time when the unit may be so
establiebed ; and at the present time (1856), the general
run of marine nominal horse-power varies from two
indicated horse-power to four indicated horse-power, that
is, from 66,000ib5. to 132,0001b5., raised one foot high per
minute, it is submitted that the unit of marine horse-power
would now be most conveniently fixed at 100,0001bs, raised
one foot high per minute. Until, however, some definite
measure of the unite be legally recognised, it is considered
advisable in matters of scientific inquiry like the present
to adhere to the measure of the unit originally proposed by
Watt—viz., 33,0001b5. raised one foot high per minute;
designating this scale of measurement as the " indicated
horse-power," thus--Ind. h. p.—and such will be the unit
referred to when horse-power is spoken of in the following
pages of this paper. Now, as to the measure of the unit of
tonnage by which the sizes of ships are to be spoken of and
compared, we have already observed that under the Mer-
chant Shipping Act passed in the year 1854, the unit of
tonnage is based on the internal roomage of ships available
for cargo • that all ships built since May, 1555, are regis-
tered under this act; but the re-measurement and re-regis-
tration of ships built previously to 1855 is not made com-
pulsory. Shipowners have the privilege of re-registering
under the act of 1854 such vessels as they may select for
that purpose • consequently, our present registration is
mixed, and the various units of tonnage measurement thus
embraced under our present tonnage registration have no
definite ratio to each other, or to the tons weight of cargo
that ships will carry. The comparative merits or demerits
of these various systems of registration for fiscal purposes
need not be here discussed. Suffice it to say that in none
of these systems has any notice whatever been taken of the
measurements which constitute displacement ; and as dis-
placement is an essential element in any scientific investi-
gation as to the locomotive performance of steam-ships with
reference to the power employed and speed attained, it fol-
lows that our present registration of shipping, even under
the Act of 1854, does not afford statistical data of Bitch a
character as to be available for science in the matter of coin-
paring the merits in a locomotive or dynamic point of view,
of the various models of types of form by which steam-ships
have been constructed. It issubtnittedfor theconeideration of
the British Association that national advancement in mari-
time affairs, especially in regard to transport economy,
would be promoted by our public registration of shipping
in general, and of steam-shipping in particular, being a
systematisrequireded as to embrace not only the roomage measure-
of
for fiscal purposes, but also, in addition,
the data
, those details of
speed
aed
powerdisplacement
derivedwhich, inro
from
combination with
formancee of ships, are necessary to scientific investigation
in determining the relative dynamic merits of different types
of form of steam-ships. It must be borne in mind that it is
the public, the consumers of merchandise who must ulti-
mately bear all the expenses connected with the transport
ysauner
anti
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avr
nerd,e
gsl merchandise. l
or.c o
Bsi
tl performed.
Bad esi rhu oprs
,omratel
imported
enhance the price of cotton and all other similar raw t.
cßaonarddn deliverysaliniisaliinodoti
other
uecraocinhi
ships
imported for the production of export manufactures.
This enhanced price restricts demand, thus curtailing the
sources of employment, so that every bad ship, whether em-
ployed in the import or export trade is, of itself, a public
nuisance, a prevalent bad type of ships would be a public
calamity, and progressive improvement would be a public
benefit. It has been said that the interests ofshipown e
on
is in itself a sufficient guarantee for insuring the adoption of
the type of ships best adapted for mercantile steam-trans-
port economy. It is scarcely fair to base any argument
interested motives, but as that argument has been raised it
must be noticed. Undoubtedly, each shipowner has an in-
dividual interest in hie own ships being the beat afloat, but