NAT'L BOLT & PIPE MACHINERY CO.,

Mfrs. of Hand and Power Bolt and Pipe Cutters, Bolt Pointers, Bolt

Headers, Hot and Cold Pressed Nut Machinery, Taps and Dies, etc. Send

for Cir. Cleveland, O.

* * * * *

[Illustration: ELEVATORS

HAND POWER AND HYDRAULIC

FREIGHT AND PASSENGER

SHAFTING PULLEYS & HANGERS

S. GRAVES & SON ROCHESTER N.Y.]

* * * * *

BOILER COVERINGS.

WITH THE "AIR SPACE" IMPROVEMENTS.

THE CHALMERS-SPENCE CO., FOOT E. 9TH ST., NEW YORK. Sole owners of the

Air Space Patents.

* * * * *

THE TANITE CO.,

STROUDSBURG, PA.

EMERY WHEELS AND GRINDERS.

LONDON--9 St. Andrews St., Holborn Viaduct, E. C.

LIVERPOOL--42 The Temple, Dale St.

GEO. PLACE, 121 Chambers St., New York Agent.

* * * * *

[Illustration: ROCK DRILLING MACHINES

AND

AIR COMPRESSORS

MANUFACTURED BY BURLEIGH ROCK DRILL CO

FITCHBURG MASS.

SEND FOR PAMPHLET.]

* * * * *

Scientific American, Volume 40, No. 13, March 29, 1879 A Weekly Journal of Practical Information, Art, Science, Mechanics, Chemistry, and Manufactures · 第 156 / 162 题