The climax. [volume] (Richmond, Madison County, Ky.) 1887-1897, 1888-03-28
A MARVELLOUS MACHINE.
II Has Ruled a. High Forty Thousand
Lines to the Inch.

II has IuleO a. HIGH a. Forty Thousand
Lines to the Inch.
Dr. H. A. Rowland, of the Johns Hop
kins University. has a new engine for
ruling his plates for spectrum analysis
or decomposition of light. This en-
CINE was made entirely at the universe
ty under his personal supervision, and
is the result of the most careful, pains
taking effort. The most important
part of 1.-THE screw and its attach
ments for regulating the width of the
lineS-was carefully ground under
water kept at constant temperature.
SO as to avoid all error arising from ex-
pansiOn and contraction, and is guarded
against so small an error as One-hun-
dred-thousandth of an inch. The en-
CINE is run by water power. and is in
closed in a glass case aud kept in
dOuble-walled brick chamber in the
basement, so as to provide as equable
temperature as possible. So delicate
is the machinery that while it is run
ming the case is kept closed, as the heat
from a person's body would affect it
The new machine at first was not salts
factory. but now the worst ruled plates
by it are better than the best ruled by the
old one. The old one hardly ruled
more than 10000 lines TO the inch,
while the new one has ruled as high as
40. 900. and can be graduated to rule
an almost infinite number, but the
metal usually crumbles, and the lines
run into each other above twenty thou
sand to the inch. The plates are highly
polished. and are made of what is
known as speculum metal, though glass
is sometimes used for experimental
purposes. The prepared plate is placed
on the machine, aud the screw regu-
lated to the required distance, and
when the machine starts it moves the
plate the distance, say, one-twenty-
thOusandth of an inch. and a small
diamond point runs across and draws
the line while the plate is stationary.
1t is matter of infinite care, and
several days are necessary for ruling
plate three or four inches in dia-
meter. The diamond point can be 80
arranged AS to vary every fiftieth or
One-hundrcdth line. while at the end Of
! the engine s small counting machine
for recording the number Of lines
] drawn. In an adjoining room is a very
costly instrument for measuring the
width Of the lines, and so marvelOusly
accurate is it that an error of one hun
dred-thousandth part of an inch. or
even less. can be detected. The rulings
Of this machine are the finest in the
world, and have been sent to different
parts of the scholarly portion of it, one
of the largest and best plates being
presented 10 Prof Helmholtz, the
world-famous physicist of Berlin. If a
perfect m achine means one that per-
fectly does the work it was designed
for this is probably the most perfect
one in the world. Baltimore San.
Thomas Peterson, Of Perth Amboy,
n. j.. reioices in the distiction of hav.
ing been the first coIored man 10 cast
Il vote in the United States. This i'm
poriant bit of paper was dropped in
the ballot-box March 81. 1870, the
morning after the adoption of the
Fifteenth amendment. A few years ago
the citizens Of Perth Amboy presented
Peterson with gold medal in com.
nemoration Of the Interesting event
49,
"A Maidstone with nroieHs Of gyp'
som. proi ably sucked Up in q -SEtcr-
spout, fell in a recent shower in ! ,anee,
/ no rnn take TIE CIINAx2