New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1854-02-02
LETTERS FROM THE PEOPLE,
THE ENGINES OF THE SAN FRANCISCO.


To as ES,,s, Of Tas N TreS~ -,
Sin; In your paper Of Monday in the hsding article
there are some points OF information with regard to the
steamship San Francisco many of which are correct but
otbe se erroneous fact and in my opinion in theory
Presrne tia, your Efforts are always directed to the a.
,anmeni Of the truth propose in relation 10 some oil your
statements to give you facts which do not agree precisely
with the information when has Deeh oeen io'"ery o'-
CURED by you
Now your idea OF the action OF an cir pump perfectly
eorec, 20 that agree upon our data and your state
uerts In regard 20 the different methods oil working the
a., nnmrs Of o.cators correct and moreover
the whole ground Whether these methods are good or
bad pertinent TO the present inquiry and were to
srnress an opinion thereon mi ht be treadng the
ices Of engineers older and experienced than myself
A forged crank however, in the eighteen and hreequar
Ter inch main shaft twenty nine feet long, of the San
Francisco would have been rather difficult piece Of
work and her shaft with such crook in If would not have
been much improved IN renSth
The San Francisco pump was CONTRACTED you des-
cr;be and NAV at low veoctes have struggled plunged
and kicked supposed in your article bat such pungng
instead Of bre ing down would have tended 20 preserve
the pump (G The piston moves through 60 per cent of
IFS stroke png the water up in front of it. and while the
engine accelerating the ply wheel but Just the deli
very valves open and the piston over its whole area
strikes the solid water it, motion is as you say, checked
owing 10 insuficiency of fly wheel The shock the
iston therefore much less than if il forced along
by fly wheel sufficient to drive it through without slack
ening It's speed is the in ordinary air pump
This plunging would no doubt inure the air pump en-
CINE but that resisted all the strain which it sub
ieeted during the gale (6 This pump at each
half stroke delivered only onefh of the water put in
motion by ordinary air pump, and therefore sub
iect 10 only one fifth the shock (d).
The very simple and efficient independent pumps of Mr.
WorthingtoD, two of which were on board of the San
Francisco and did good service in keeping her free and
relieving her of shipped water, work without any fly wheel
being simply steam and water cylinders on single piston
rod they relieved Of their load before the
end and the of each stroke that their
ptons jump pause, and jump again and when their sue
- no. thnsr Hufr
csely similar that erformed by air pump. These
prmps break down precisely for the reason that
they pause they take the strain and have gradually
kicked themselves into public favor and are in in al
every ship Gu; Of this port jumping into their work
whenever needed fc
Mr. Worthington moreover has constructed an air pump
on the same plan which has for many months worked well
at some sixty revolutions per minute and there is in
the Newburgh cotton factory, an ordinary single
acting air pump, driven by an Independent engine which
has been doing good service these six years and there il
at least Scotch ship which has an Independent air
pumpJd)
The gentlemen, whoever they were, who complacenty
ascrbed the original bad in the the San Francisco,
Mr. j p Prisons Patent Condenser, had some little
for their compiacency as good vacuum with the
so same pump unaltered was obtained as soon a. his
tubes were removed But the failure of this particular
condenser and its imperfect action in at least three Of the
ships named by you which fact will prove concusively
If called upen failing to supply them with enough fresh
water affords no lair ground for warning the public
aganst building other condenses the principle
Il is bat reasonable suppose that the ingenious inventor
will ere long improve his condenser that it shall perform
with all the success which he now believes it aains
When the Atlantic air pump broke down on her first
trip. and the Battles her second men did not say
that sideever engines and upright single acting pumps
were imperfect in theory general plan, but they looked
for defects in workmanship which sometimes unayoid
able SO in the present ease defect in the piston rod
which it is known existed and the twisting rtoron
strain and the actual load to which that pump
was subjected, while the San Franciscos engines
running fast in the trough o heavy afford sufficient
reasons for the break down. But such an accident fur
nishes no good for condemnng the whole plan OF
engines which after all they underwent il is said in
one newspaper perfect when they left the shop and
which engineers think present many advantages
the Of strength, simplicity efficiency and economy
Of space.
have however, desire 10 write treatise on her
engines or advantages of independent air pump,
contenng myself with expressing an opinion somewhat
contrary TO yours as far as theory 10 concerned and
stating the facts that the original difficulty in this ship
arose entirely from the unsuccessful action OF the fresh
water condenser and that the air pump broke down when
doing duty far beyond tina, for which calculated
Nsu- IcJk, Jan. "a, 1854 PUMP