676

THE COLLIERY GUARDIAN.

March 28, 1913.

IMPORTANT NEW DEVELOPMENT IN GAS

ENGINE DESIGN

THE •' DUPLEX" VALVELESS GAS ENGINE.

The simplest and therefore the most reliable Engine on the market.

THE

Duplex

(Patent)

Valveless Gas Engine

NO

NO

NO

NO

NO

NO

ADMISSION VALVES.

EXHAUST VALVES.

CAMS.

SIDE SHAFTS.

VALVE POCKETS.

INTRICATE CASTINGS.

Easy to Lubricate. Easy to Overhaul. Steady Running.

The “ Duplex ” represents the highest standard of Gas Engine Construction.

In Single Units from 200 H.P. up to 4,000 H.P. or larger if required.

Write for Booklet.

ClaflmPlattB

MANCHESTER and LONDON.



NOW READY.—Bound in Cloth, 10s. 6d. ; Paper Covers, 8s. 6d.

SUPPLEMENTARY VOLUME

TO

The Mechanical Engineering of Collieries.

By T. CAMPBELL FUTERS.

Publishers: THE COLLIERY GUARDIAN CO. LTD., 30 & 31, Eurnival Street, Holborn, London, E.C.

NO MORE PIT CAGE ACCIDENTS!

Ascending
and
Descending
Cages
Safeguarded,

No
Interference
with
Winding.

Starting
in the
Wrong
Direction
Prevented.

i#

1





Safety
assured
with
‘THE

VISOR.’

The most

Effective
Machine on
the
Market.

Over 200
at work.

Write for
particalars to

JOHN WOOD & SONS

Ltd.,

Telephone : 55 Wigan.

Engineers. WIGAN. Telegrams : “ Haulage, Wigan.”