The daily union. [volume] (Washington [D.C.]) 1845-1857, 1846-01-26

| Communicated
To the Editor efth4 UaiOai
Sra | have observed that the Philadelphia
Ledger OF the 2sth instant states that resolution
| on the inquiry into the modern Improvement in
steam, and particularly into the merits Of Lieut..
Hunters propeller, has been introduced into the
Senate by MIR. fuee, Of Florida and further that
committee on science and the arts, constituted by
the Franklin institute Of the State OF Pennsylvania
or the promoton Of the arts reported on the
relative merits Of the Loper propeller and Hunters
submerged wheels; and that u will be seen by the
report Of this COMMITTEES % tho Franklin Institute
that the information required py MIR. Yulees reso-
luton 10 therein furnished.
We nave soen IA msmoIT on the application Of
sIeam power 10 ocean and naval vessels, which has
been presented To the naval committee OF the Senate
consequent on the same resolution of Mr.. Yulec
together with authentic and official prouf that tho
submerged propeller Of Lieut.. Hunt has inlpelled
several vessels, unaided by wind or tide ten miles
per hour and that vessel OF over ! 900 tons has
beaten by one day the naval side-xhtel steamer
MlssissiPPiin passage fow Norfolk to Pensa-
cola.
Notwithstanding this result il should he recollect-
ed that the vessel alluded was little more than
development Of tue Propulsiye principle Itself yet
this has, beyond all question, attained a speed by
steam power alone OF ten miles per hour and that
the efficiency OF the Hunter propeller is now vastly
increased and It's mechanical arrangement perfected,
as VIII be shortly manifested IN the Performance OF
the naval IRON steamer nearly ready for service
at Pittsbnrgh, Pennsylyana. II is To DC regretted
hat the resolution OF the Franklin Institute should
hive been based on dau so slight With engines
Just from the foundry, and with the propeler-shah
bearings OF the SPENCE defective as 10 deprive
this vessel partly Of her efficiency, (as was clearly
manifested in the trial alluded TO- il seems exraof
binary that this committee, In It's wisdom, should
have recommended "thn, the further use Of Hun.
ter's wheels should be abandoned" The allusion
made 10 the notice Of the report in the Ledger that
the United States steamer Union has been aid up
for the last year at the Washington navy-yurd, tends
alike, with The tone Of the report Of the committee
81 the Franklin institute, TO convey u false impress.
SION that this vessel discontinued in service be-
cause Of the inctheieney OF Hunters propeller,
when no such thing is alleged to be the case.
The truth u, her boilers burned out, and
have not yet been replaced. With regard to tho
steamer Melane, Hunters propeller has never
moved IN her and In relation TO the George NJ
Bib, she has never had trial; that vessel not
yet having reached the sea- and the trial of her hay-
ing been officially prohibited until she reached that
point With regard TO the Water Witch with Hun
iers propeller, she was impeed ten miles per hour,
AS the Official reports OF her commander will show.
With these propeDers she also beat the United
States steamer Engineer; yet this same Water
Witch was altered, and Loper's pro eller applied To
her, and Notwithstanding she was heightened, she
has not since attained The same speed, and beat
en- by the steamer Engineer, which she had so easily
extract from the official report of the commander
Of the Water Witch, with Hunters propeller II
says: ION the evening OF the 18th Of April, lS4J,
she (ihe Water Wnch) lowed the ' dnted States
shp Saratoga from Norfolk to Hampton Roads, dis
ant sixteen miles, IN two hours forty minutes,
against strong food-tde and northwest wind.
And again, on the morning Of the 18th, she toyged
the United States ship st. Mary's from, and to, the
same places in two hours and fifteen minutes against
the tide, and returned to Norfolk in one hour and
twenty minutes, tide in her favor.
Had the franklin committee assumed the above
data on which to found the report and recommends
ton IN relation to these propellers, il would have
shown itself better acquainted with the subject on
which u has hazarded its judgment and graiui.O,u
advice, (purportiDg TO he the resolution
Of senator Yulee,) and would have afforded somo
slight reason for belief in its total disnteresedness
in the subect-matter which from its national char
acter at this crisis, places it far above considerations
pertaining TO the pecuniary gain of local establish
ment . -'..
WEST AND BY SOUTH.
The following is the report alluded to in the above
communication:
HALL or THE FRAsxLIN INSTITUTE,
900 "' Philadelphia, Dec. Is, lSi5.
The Committee on Science and the Arts, consti-
tuted by the Franklin Institute OF the State Of
pennsylvn1ia, for the promotion of the mechanic
arts, TO whom was referred application from the
Hon. r. J. Walker, Secretary Of the Treasury, for
their opinion as to the relative merits of Loper's
propeller and Hunters submerged wheels, present
the following 1885,, ......
4 To comprehend the construction and action Of
Huniers submerged wheel we have only to ina
CINE an ordinary paddle wheel, moving the side
Of boat, around vertical instead Of a horizontal
axis, with the paddles attached to waer-tght and
empty cylindrical drum, and the whole immersed
helo he rfac of he WI & nh emf
in the open water, is evident that The revolution
of pair of such wheels would produce no motion
in the vessel, since any two opposite paddles must
exactly counteract each other, That the boat may
be propelled at ALL therefore, is necessary that the
greater part OF the paddles be made to revolve in
dead water by surrounding them with casing Of
wood or iron. A very few, three or four, of the
outside paddles thus rendered efficient in the
propulsion of the vessel, while all the force
qriired to move the others through the water il
wasted. .. ..4,... ...t. ~.
This propeller, therefore, differs in its action
from the ordinary sidc.whccls Of steamboats, only
in the circumstance that in the latter the inefficient
paddles move through the air, medium present
ing slight resistance while in the former, the inefli
cieDt paddles move through the water, medium of
great resistance. lis perfectly manifest then, that
the latter must require vastly greater power than
the former to produce the same effect.
The Lopez propeller is one Of the many varieties
| ofthe screw propeller--an arrangement which, IN
employed for driving vessels through the WATER and
which possesses the advantage so important in
many cases. and especially in war-Sosses, OF being
| submerged under the water As a comparison OF
the Lopez propeller with wheels of the same class
10 not asked OF the committee, II is not deemed
ccssary to describe its pecularities in this report
/ For simple and perfectly satisfactory COMPARE
son Of the relative merits of the two propellers in
question, the best test is that which would be offer
ed by their respective operations il attached to the
same vessel, md set in motion by the same engine.
Such comparison is fortunately presented by
ries of experiments made with the United States
steamship Spencer, the details (which given in
the printed reports of Capt Alex. v. Frazer. As
,he vessel and engine were the in both cases,
il il not necessary thnt they should be described
since for mere comparison il is the variable guam
titles only that need enter into the computation.
| STEAssHIr SPENCER, WITH HUsTER's PRorELLERs.
| In trial made on the New York bay, in Sep
TENDER, 1874, with Hunters submerged wheels at
tached to this vessel il appears from Capt Fruzer's
report that she moved through the water with a
speed Of s miles an hour. Now the work ac-
=. al. =. ooty,