September 1914, THE COLLIERY GUARDIAN. 513 PLOWRIGHT BROS, LTD Brampton Iron Works, Chesterfield MINE FANS SECTION OF SCREENING PLANT AT BENTLEY COLLIERY, DONCASTER.^ CONSIDERABLY OVER DAVIDSON & Co. Ltd Sirocco Engineering Works, BELFAST WORK IN BRITAIN COLONIES. •• TRADE • * • • MARK Speciality COAL SCREENING & CONVEYING Deliver more air at less cost for power than the ordinary paddle blade Fan. Sirocco Fans can be arranged for reversal of air current. 100 PLANTS H Estimates and Designs on application. Agent for South Wales: A. LEIGHTON STEVENS, 15, Fields Road, Newport, Mon. SURVEYING INSTRUMENTS H0PKINS0N-FERRANT1 Davis’s Cranked Dial Theodolites Levels, Barometers etc DAVIS’S IMPROVED HEDLEY DIAL WITH ENABLING SIGHTS TO BE TAKEN TO ANY DEGREE FROM LEVEL TO 90 DEGS. UP OR DOWN. CRANKED LIMB, Davis’s Surveying Instruments are used in the majority of Mines in the United Kingdom, the Colonies, and other parts of the World. PLOTTING INSTRUMENTS for Railways, Mining Engineering, and Field work. SEND FOR LIST PATENT STOP VALVE For Steam and High Pressure Water Service. The Greatest Advance in PRINCIPLE : Converting the pressure of the fluid into velocity and re- converting the velocity into pressure, thereby passing an amount of steam equal to full carrying capacity of pipe. SELLING POINTS: Passes same quantity of steam as a full- bore valve. Seats half diameter of ordinary sluice valve, therefore halves possible leakage. Graded opening—no sudden rush of steam in opening. Is not subject to wedging action or mechanical strain. When the valve is open the seats are pro- tected from the flowing fluid by the eyepiece. Always easy to open and close under pressure. Discs and Seats of HOPKINSON’S “ PLAT NAM ” METAL. Suitable with Superheated Steam. Illustrated Specifications and Catalogue free on application. Valve Construction of the Tinies. U) JOHN DAVIS & SON /Tleirhirl I TH ALL SAINTS works, derby; IUuI Dj I 1 Uaj & 17, Victoria St., Westminster, London, S.W. Telegrams—“ Davis, Derby.” Telephone—240 Derby J. HOPKINSON & Co. Ld Makers of Patent Valves and Patent Safety Boiler Mountings, HUDDERSFIELD. London, Glasgow, Edinburgh, Cardiff, Oldham, Paris & St. Petersburg. No. 275.