The daily union. [volume] (Washington [D.C.]) 1845-1857, 1845-08-01
THE Lopez PROPELLER.

THE Lopez PROPELLER
The following letter of Capt. Alexander " Fra
SER of the revenue service, is contained IN his Off
cial report of the trial of speed made short time
since in our river and bay, with the steam-cutter
Spencer subsequent to the application of Lopez pro-
pellers by Messrs. Merrick & Towne, under the SUI
pervision of Capt Loper.-Phil Ledger
WASHINGTON CRY, May 80, ls45.
SIR: have the honor to submit the annexed re-
port of the trial of the United States steam
ship Spencer, made agreeably to your order of the
10th inst.
1t is but Justice to Captain Loper the patentee of
the propeller state, that in making the alterations
in the mode of propulsion the cylinders, DC. have
not been disturbed but remain in the same position
as when furnished with Hunters submerged wheels
rendering it, therefore, necessary to use cog
wheel gearing, and, owing TO the great length of the
shafts requiring bearings TO each, increasing the
friction very greatly. The peculiar model Of the
vessel is likewise to be considered, as interfering
terally with her speed.
The relative revolutions of the engines and propel-
ers are as of the former to one and one-quarer
Of the latter.
Sceptical as ! was relative to favorable result,
am free confess the performances have greatly
cecded my expectations; and | have no doubt that
were the bottom of ordinary form, and the ynders
so placed as to take direct hold of the shafts still
greater increase of speed would be the result
On my arrival at Philadelphia, | found that cir
cumstances over which neither Captain Lopez nor
Messrs Merrick q Towne had any control, delayed
the completion of the work beyond the time spec-
fed in the contracts and she was not ready for trial
until the Goth instant, when few turns were taken
in the vicinity of the city, for the purpose of seeing
that everything was in working order.
The machinery working well, fixed upon the
2lst for making the trial; and in order prevent any
dispute relative TO distances, tide, &c, selected the
straight reach of the river between Chester and
Ma H.. eiy nassa hefu thosa
points. The distances established by the super
intendent of the coast survey"
During the above trial, the Vice President Hon.
C. j. Ingerso, Commodore Elliott, and Captain
Gauntt, of the navy, a committee OF the Franklin
Institute and several other gentlemen interested in
steam navigation, were present, and noted the time
In the evening anchored near Christian creek
cleaned the furnaces, &c. At daylight of the 22d
got under way and proceeded down the bay, the
machinery working smoother as We progressed In
the evening, the wind hauling to the eastward, and
the furnaces having become foul from the bad quail
ity of the COAL anchored at the Delaware breakwa-
ter, and cleaned out.
On the Gath, got under way at TAO, a. M, wind
light and variable, the flood ide running with great
rapdity, and the weather threatening.
When abreast of Great Egg Harbor, the wind
veered to northeast, blowing fresh, and bringing in
head sea, hauling more northerly we approach
ed Barnegat, and increasing in force This wind
and sea we had TO contend with the whole distance
X,
could be expected. The distances and times in
which they were made, are hereunto annexed, and
show great increase of speed all former trials
The coal procured at Philadelphia contained
very large proportion of slate which foued the fur
naces very rapidly, making it necessary very fire.
quently to let the fires run down--the contracted
space for the engine-room rendering it impossible to
remain below after the fires are raked out or until
the cnders partially cooled
Some fifty feet in the body of the vessel is occu-
pied by machinery; and, notwithstanding that cur
rent of air is forced into the engineer room by a
blower placed in the hatchway, the thermometer
frequently ranges from 1909 to 1900 Fahrenheit.
Were the machinery adapted to this mode of pro-
pulson, the whole space required for its accommo-
dation would not exceed Is feet in the afer-hold;
enabling her to carry full supply Of fuel, and to
accommodate the crew comfortably. Under the
present arrangement, but six days fuel can be
ried, and the principal part of that quantity above
the water line.
The George M. Bib, built at Pittsburg, upwards
of 400 tons admeasurement, is so much occupied by
machinery, that it has been found necessary to
move the accommodations for the captain to the
SPAR deck, in order to provide space for fuel.
1t may not be irrelevant to remark, that am ex-
ceedingly fearful that the same error will be COM
mitted in the two side-wheel steamships now in
course Of Notwithstanding understood from
the engineer-n-chief that he required about forty
feet in length, with the whole beam and depth of the
vessels for machinery There are at present two side
wheel steamships building at New York for the
Mexican government; and, Notwithstanding the di-
mansions the as those building for the rev.
enue service, and the engines low pressure, the
whole length occupied by machinery is but twenty
six feet. Information has just reached the depart
ment that the revenue steamship Jefferson (on the
plan of Captain Ercsson) has broken her propeller
for the second time; and the same accident has hap
pened to the Legare.
would respectfully recommend that, the ma
chinery of the abovenamed vessels is adapted to
Loper's as well as Ericsson's propeller; and as the
propeller may be made, sent to the vessels, and APP
piled by their engineers that that OF Lopez may
be used am satisfied, by my own observation,
well as the assurances Of individuals who
gagged in steam navigation, that the Lopez propeller
is far superior to the other in every point Of view,
particularly in strength and in durability.
have the honor to be, very respectfully sir, your
obedent servant,
ALEXANDER V. FRASER,
Capt U. S. Rev. Marine
Hon. ROBERT J. WALKER,
Secretary of the Treasury, Washington.
I Axes he hety nd Mar.