The Portland daily press. [volume] (Portland, Me.) 1862-1921, 1895-08-29

in every direction. He can widen this
crack to an inch or more or close it en-
tirely at will. From here he steers the
vessel by directing his assistant at the
wheel and from here he directs every
officer Of the ship in the performance OF
every necessary duty. He has electric and
speaking tube communication with each
gun and torpedo station, but when he
desires to give the same order to all, or
part, he communicates to central station
down below in the ship, and from there
it is distributed. Thus here in this con-
ming tower the captain finds out the
range or distance of the enemy's ship at
any moment and communicates 1T to the
gunners at least a mary ellous electrical
instrument finds this out for him and
tells him at any moment, so that he may
inform the gunners, who are looking
through those tiny holes above mentioned
Thus they know how much to lower or
raise the gun, which Of course is deter
mined by the range.
This marvellous instrument is the
FISKE RANGE FINDER.
In the coming tower there is simply a
metal stand with various electric buttons
and graduated scale with numberless
figures. This is connected by electric
wires with two telescopes, one at either
end of the ship. AT each telescope is an
officer They can communicate with each
other, electrically, and can thus agree to
keep the cross wires of their telescopes ;,
that is, direct them, on exactly the same
spot on the enemy's ship. 1t is essential
that they should point at exactly thes anne
spot.
It viii. DO seen that the two lines of
direction Of these telescopes conyerging at
IL I,
of the ship, between the telescopes,
the three sides of triangle. OF course
line from the apex of this triangle. that
is, the spot on the enemy's ship, extend
ing to the middle of the base line, that is
the line between the telescopes, is in
it's length the exact distance of the apex
from the ship, that is, the range of the
target. This line can be figured out by
trigonometry and this used to be done.
The captain didn't do it. 1t was all
done for him and printed in book OF
tables, for all distances. But the Fiske
rang finder is better. The captain
doesn't have to look up the range in the
book of tables. Electricity does it for him
and announces it on the scale.
Around the table that the telescope rests
on is German silver wire. By moving
the telescope the electrical resistance IN
this wire is varied The telescope is con-
stantly moored il both ships are moving
so hat it may constantly point at the
apex of the triangle Thus the. chahge
in potential in the electric clrculo i: Il
directly proportioned to the change IN
range of the object sighted on; bna1 IS,
the apex Of the triangle. by gfauuatllis'
and registering them on that scale in the
coming tower and by keeping t me- cross : ss
wires Of the telescopes on tho opJecV' inc
range may be read at any moment a 4I ny
pressing the electric button ol hno T ,5ia
meter, The pointer registering the range
in yards 49, nv.
marvellous electric current thus marvel
ously employed, does all the resi- NO mat
ter how fast either ship is gong; no mat
inc no matter how that great imaginary
t iiis' Of varies in shape, the ever chang
i frl9 distance from its apex to the centre
Of It's base is constantly registered by this