The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1888-01-28
Letter from Texas.
Correspondence of the Democratic Advocated
SrocKDALE. january II. 18s8.

STocKDALE, January IL, 1888.
If the dear old ADVOCATE will allow me a
little of its valuable space would like to offer
brief dissertation on subject purely scien-
tifc and mechanical 1t must occur to the
most superficial thinker that steam as means
for utilizing heat for motive power is very
dangerous in the hands of inexperienced or
careless operators. The frequent frightful
explosions prove this More than this, think
steam or water is very deficient, because it
| Will not yield an ounce of effective force until
its temperature is raised to 2t2o Water is a
slow conductor of heat, Notwithstanding its
| great convection, and very poor radiator.
Hence substance that is a good conductor
and prompt radiator of heat is at once prefer
able for converting heat into mechanical mo-
ton. Add to this the non-explosive nature of
another plan for utilizing heat as a motive
force, and may be the reader will patiently
hear me through. l would suggest that mer-
curry is an excellent conductor, and very
prompt radiator of heat, and / reason that
compression cannot prevent heat entering a
metallic body; therefore an engine properly
constructed, and charged with mercury, should
yield some power upon the application of
few degrees of heat. Such an engine might
be broken by great resistance, or | might say
too heavy labor, but, it hardly seems necessary
to add, could not be exploded. Some one
may ask, would you vaporize the mercury?
Oh, no.. Place two small cylinders tandem,
and one solid straight piston rod entering
each; place a small, stout metallic retort be-
tween, and communicating with the inner .endss
of the cylinders. Now arrange sn't7'u ''.'o
and pumps to transfer tb'has been tbe11as-1ttai "a
curry frSpt ba treasury Enable valves tarI
t-hoh Vi inc ia'Ja hot expanded mer- Thu
roceedftne cylinders through vat of water, line
cool the mercury promptly, into the retort the
in, alternately, thus producing reciprocat- hav
rectilinear motion. of course fire would the
placed under the retort, which would be we,
ID with mercury. Or, perhaps, better two
n would be to arrange system of metallic per
IS, on the principal of the compromising Shs
ldulum, but reversing the arrangement, SO trol
t alternate heating and expanding, and l
,ling and contracting, would give oscillating por
ton. Some one may say that such an shli
zine would be too slow for practical pur- Hi
jes. 1t should be remembered that the Do
ce of expanding or contracting metal is Ne
,rmous, and is readily convertible into great hill
ocity. | am not financially able to attempt mo
ting into practical operation the ideas fro
dely set forth here, but trust that some one nee
y give the subject herein suggested that bel
lsideration which it seems to merit. 1t is sea
too early to expect new developments in ing
chanics, in this age Of profound research St.
scientific developments. tim
Reading Captain Jack Crawford S exposure wei
tricks in rifle shooting, in last weeks AD- Ea
GATE, reminds me of seemingly impossible die
t with rifle. Thinking it may be new and wol
eresting to many of your readers, | will of
plain how it is performed. Take piece of nea
Their cardboard, or any suitable Opaque I
stance, about two inches square Tor it may IA
circuar), cut hole in it and slip it over day
muzzle and directly in front of the bead she
my accurate double sight rifle. Now wager La
lr friend you can hit any reasonable target, Sal
if good marksman you can ''knock the Col
ok OUT" although the line of sight seems lost
actually obscured, blindfolded, as it were. foc
aim gun arranged thus close the left eye lay
place the right accurately in line with the ing
sights (the usual mode of aiming); bring tioc
piece in the direction of the target and ear
m the left eye, giving that optic your men anc
attention, and the bead or aim can be ac- OF
ately drawn. Try it. wo'
PETER B. BARNES. risi