Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1897-08-06

able. BY these coi..rivances. the desired
plane Of section, previously marked
around the specimen. can quickly be
brought into parallell.m with the plane
| OF reference. This adjustment IL made
| by the assistance OF a "Starrets surface
| gauge as II stands upon the table with
It's index-point set at the exact height
above the table at which the edge o. the
| cutting-dlsk should be.
"A cutting disk guide Is rendered neces-
sary by the fact that the thin,
metal disks charged with diamond powder
ct tho edge. which are used in
tho cutting. cannot OF themselves ho.d
to a true level at least II more than
three or four inches in diameter The
cutter guide Is a solid, movable frame.
carrying two swinging adjustable hori-
zontal arms ono beneath and the
| other above the cutting disk: each arm
carries three or more adjustable steel
wheels properly adjusted TO the correct
height above the plane OF reference by
the Starret's gauge, mold tho cutting edge
to it's true level they retreat before
the advancing specimen during the cut
ting.
mo novel features have been applied
as yet to the cutting disk in this ma
/ chine, though the latest, most permanent,
and best form OF il is used.
by these contrivances any ordinary
| specimen may be very smoothly cut in
any desired plane. very exactly Tor
| planes OF ten to twelve square inches sur
| face. Since all Of these thin, cutting
| disks OF large size (ten 20 twelve inches
diameteD are warped by use. and since
tho cutter guide can only correct
thoroughly that portion Of the warped
disk which Is outside OF the specimen.
| larger surfaces can be cut with only APP
prOximate aud tOlerable accuracy until
the cutting disk can be improved as it
Is hoped that it can be. However, sec
tions Of from thirty 10 sixty square inches
Of surface have been cut with tolerable
| accuracy.
For cutting these sections. the pro-
cedure is as follows: First, cut IS
made across the specimen in the re-
quired plane by tho method above de-
scribed. one OF the faces thus obtained
is polished and cemented TO a slip OF
glass of suitable dimensions, and larger
than the section. This GLASS slip is set
into a specially constructed wooden
clamping-blOck which is then locked
firmly I'm the jaws OF the object holder
THE upper surface Of the glass slip
Is now brought into exact parallelsm
with the upper surface Of the table. This
may be done by the use OF Starrets
gauge, or preferably and more rapidly
by a spirit-leve which Is supported by
specially coutrived dwelling tripod
which stands upon the surface OF the
glass slip. This adjustment having been
made. the object-holder must he raised
until the glass slip is brought t. a slight
distance below the cutting disk. This
distance IS exactly determined by the in
sertion of a gauge called a thickness
gauge.
THE requisite pressure Is then applied
TO the object-holder and water Of lubrlca-
ton Is turned on. AS the cutter makes
It's way through the specimen. 1t leaves a
thin film or section Of the latter on the
surface cf the glass This section may
be from l-50 to l-l0O Of an inch In thinneas
as cut, and may be transparent, but there
Is no advantage in cutting il 50 thin. II
Is generally pref rable TO cut the section
somewhat thicker. and then grind II
down to the exact degree Of thinness
which under the microscope will best
show its structure, since in any case this
final grinding must always be done.
There are number Of accessory pieces
OF apparatus for extending the capacity
OF the machine and facilitating it's work.
one OF the most important is an arrange
ment by which the pressure Of the speci-
men against the cutter can be increased
al will. az the cutter penetrates the
larger specimens and the friction in
creases. Another accessory Of industrial
rather than scientific value can be at
tached TO the cutter-guide, and would
enable IT to guide several cutting-disks
arranged in gang one over another, and
AL cutting strictly parallel kerfs. by
this arrangement several slips or tablets,
from Is TO lilo of an inch'thick could be
cut in one operation from a piece OF Or
namental stone as onyx, lapis laZuli. etc.
Moreover. a pile OF such slips or tablets
temporarily cemented together by a sim
pie arrangement could be quickly and ac-
curately cut up with a few adjustments
into angular forms. squares. triangles,
hexagons. etc, for inlaid work, sleeve
studs. etc IL is believed that by using
this apparatus inlaid work could be done
economically and successfully in this
country, as it is not at present.
This apparatus has also proved itself
Of great usefulness in trimming of re-
dunGant material from cabinet specimens
or separating without injury. as it often
cannot be safely done with the hammer,
different kinds of specimens on the same
block Of stone.
THE original machine used in the geo
logical laboratory Of Nassar College IL
the only one yet made; IL has proved its
by the fact that while it has
been nearly twelve years in use. it is IN
as perfect order to-day as when first
made; it has proved its practicaDility by
the fact that the young lady students
cut sections by IL constantly with great
success (some Of this work having been
exhibited at the Chicago Columbian Ex-
position. and that on several occasions
work has been done with IT for promi-
nent scientists and jewellers which they
had not found 1t practicable to get done
elsewhere.
1.-THE inventor has made no special at
tennis to introduce IL elsewhere though
he has secured Il very strong patent FOR
it's various details TO prevent inefficient
and discrediting limitations OF IT, II has
evidently very important uses. both for
the scientist and lapiiary, but IL would
be of no use unless made by the very
best workmanship as an instrument OF
precision. IL a manufacturing firm capa-
bic OF doing good work can be found 10
undertake. it's manufacture and sale 1t
would be put or the market for public
use WILLIAM b. DWIGHT,
OF Natural History. Vassar
College Poughkeepsie, y. Y"
Claims to he the Messiah.
BOSTON AUGUST "A sppcfai to the