The Seattle post-intelligencer. [volume] (Seattle, Wash. Terr. [Wash.]) 1888-1914, 1898-03-27

iege have been carrying on series Of
experiments with propeiiers or Cayuga
lake. They rugged UP steam launch with
a false bow. Whic:l was designed 30 carry
a small propeller down In the water ahead
OF TIE boat AS the boat steamed forward
the little propeller ahead of II WAS forced
10 rrvoive. As Il was connected with deli
cate measuring Instruments. the character
OF It's performance could be determined ac-
eurateiy by those on board the boat A.
tached to the small propeller Was a belt
rope which CONNECTED with an inst rumeni
known as a tachometer which measured
It's revolutions. A clock with u seconds
break Indicated the speed OF the appar-
atus forward through the water. The APP
paratus was tried over a course 1900 feet
long. The course Was divided into 10
parts Of l9o feet each Various kinds Of
propeliers were tried. some having long
ard narrow blades. some having short and
thick blades, some wiki four blades and
others with three. These experiments are
still being carried on. and the general re-
suits. when plotted. VIII be very valuable
to marine engineers.
Working the Trolley Truck.
But. after all, these efforts are in
measure crude because the medium
which carried the propeller through the
water Was itself somewhat influenced By
the resistance OF the water. and also by
the resistance 81 The propeller In front.
But the trolley truck. proceeding along the
newly made tank. Will not be influenced
In the least by the performance Of the APP
paratus beneath Il. Furthermore. some
experiments will now be possible which
were not possible with the boat For III
stance. there is always a certain amount
of intevaction between a ship and her llro-
nellsr. and the resistance from this com
bina,ion Is quite different from The simple
resistance that IS generated by the for
ward motion OF the boat through the va
ter This interaetlon VIII he studied bv
means OF rropellors inserted In the water
Just behind the model. bat uaconnette led d.
rectiy herewith Fer Determining the re-
Sistance Of model boat ana her propeller
teere will b.. special trolley truck cana
BILE of carrying forward the model. ara
provided with means for running the pro-
peller steadily at any speed This trurk
viii also be provided with means Tor meas
uring tho thrust development h. The M
peiier as we'll rs the resistance OF The shin
The models are usually tried az varfai,s
speeds and "a vari0us iebths Of irsrrey-
sioa which = varied by adding ar snb-
trGcting ballast They are plsa ,rad =.
two or More SETS OF trims. or slsiew..n -.
eilnaiions. sveh AZ world naturally be as
stunned by ,esse, xhen nifrh{i,.. ,rs rott
s}g through heavy waves
IL IS the desire OF the ('7-,.e1 ,,,..s..
To make experiments which w3l bs 49,,
ia the lire ct pure science lhan In he
ane OF commercial scierce The 49,, g. -
establish q set Of general rules or ia.,s
which can be nsed by constructors v,h,sn
enoft- are entirely commercial. Their Ia,
IS 80 point oiit exactly what every kind %
propeller will do. What every shap,, IF boat
WIZ 90 nnder varying conditions how
much power woufi b., needed to n,orsi
certain boats az certain speeds and tho
Enss'a iions which would govern saeve frr-
formauces, These facts arc 20 be asrer-
iataed merely for the benefit % science:
tbsn II the various governments ur shin
builders desire 10 take advantage II them.
and go construct very fast vessels. or