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SCIENCE AND INVENTION-(Continued) placed and clamped rather freely by a
coarsely threaded hand nut, and finally DEPARTMENT OF
pinched tightly by a set screw, the tapENGINEERING
ping being done in a lathe or tapping
machine as desired. Civil, Mecbanical, Electrical
A is a cast-iron holder with a pipe and Chemical Engineering
handle; and fitted into it is the steel New Laboratories and Excellent Equipment. Beautiful site within four miles of Boston. Preparatory Department for
sleeve B, which has at one end two turns students who have had engineering practice, but insufficient of a very coarse thread whereon is preparation for college work.
For information concerning courses and positions of graduates, address
H. G. CHASE, Secretary,
Tufts College P. O., Mass.
The University of Rochester
A College of Liberal Arts
Rochester, N. Y.
screwed the hand nut C. The pin c prevents the sleeve. B from turning in the holder A. Inside B is the inner sleeve D, with the recess d to receive the nut blanks E. A key F prevents D from turning. At its rear end is fitted a disc G, upon which bears the set screw I. whereby the nuts are clamped in.
The method of operation is to place the nuts in the recess d, and screw up the nut C by land, which is very quickly done. Then a small part of a turn of the set screw I with a wrench, clamps all firmly for the tapping, upon the completion of which the operations are reversed.
EVERETT E. KENT
IN stereoscopes, as is well known, plas-
tic vision is ensured through the comCorporations.
bination of two separate views of the 84 State Street, BOSTON
same object, corresponding to the images formed by the original in each eye respectively. The superposition of these
two images produces an impression much llantion The Technical World.
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SCIENCE AND INVENTION-(Continued)
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That similar effects are possible in the
case of "monocular" vision, the picture O'MEARA & BROCK, Patent Attys., 918 F. Street, N. W., Washington, D. C. NEW YORK OFFICE, 290 Broadway, New York City: being inspected with one eye only, is
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When viewing, with one eye, photo24 Years Practice. Personal Service Guaranteed. graphs taken with objectives of a focal SIGGERS & SIGGERS, Patent Lawyors, distance noticeably inferior to the so
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plasticity which we obtain through the
direct inspection of the object the Every me
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