August 28, 1914. THE COLLIERY GUARDIAN. 461 Walter Scon Ltd. Leeds, LEEDS STEEL WORKS, England. - MANUFACTURERS OF BRITISH STANDARD ROLLED STEEL JOISTS, CHANNELS TRAMRAILS AND PERMANENT WAY RAILS, &c. He?d Frame. Erected in Work? for inspection. ■’ ■■ Example of 10 in. x 6 in. x 42]lb.IR.S Joists^curved for°Framework to Roadway- ROLLED STEEL JOISTS for PIT PROPS, FRAMEWORK TO ROADWAYS. &c. STRUCTURAL STEELWORK FOR BUILDINGS, &c. Mild Steel Blooms, Billets, Slabs, Tinbars, Rounds & Flats. Rolls cut for Special Sections and to approved quantities. Books of Sections and other information on application. PLOWRIGHT BROS. LTD., Brampton Iron Works, Chesterfield. Speciality GOAL SCREENING & CONVEYING. • '1 ■,y £ ,e‘‘- SECTION OF SCREENING PLANT AT BENTLEY COLLIERY, DONCASTER. CONSIDERABLY OVER 100 PLANTS H Estimates and Designs on application. Agent for South Wales: A. LEIGHTON STEVENS, 16, Fields Road, Newport, Mon. WORK IN BRITAIN COLONIES. Price 3s. 6d. post free. A Practical Handbook for Colliery Electricians. Electric Circuit Problems in Mines and Factories, — BY — ELLIS H. CRAPPER, B.Eng., M.I.E.E., Head of the Department of Electrical Engineering at the University of Sheffi' til. THE COLLIERY GUARDIAN CO. LTD. 30 & 31, Furnival Street, Holborn, London, E C. “VALOR” OIL CABINETS. Price from 39/- to 120/- You will obtain, by using the “ VALOR ” Oil Storage Cabinet, the most economical, cleanly, and the only perfect system of storing ALL KINDS of oil for daily use. The quantity of oil lost in leakage from barrels on tap is considerable, and greatly increases the risk of fire. The saving of this leakage will pay for the Cabinet in a short time and also obviate any danger. Taps in barrels or tanks are often left running, and measures overflow—any overflow runs back into the well of the Cabinet. Capacity 50 30 20 12 6 gallons. Price 49- 431- 401- 331- 281- each. THE MONEY YOU WASTE every week through not filtering your dirty oil would soon pay for the “Valor” Patent Oil Filter —AND LEAVE A HANDSOME PROFIT BESIDES! Full Descriptive Lists will be sent on application to THE VALOR CO. LTD., Rocky Lane, Aston Cross, BIRMINGHAM. PATENT “MAC” VALVE. Figure 8200—Inside Scx»e'w Figure 8205—Outside Scx’e'w Suitable for the Highest Steam Pressures. Fitted with Hopkinson’sPlatnam ” Metal Renewable Valve and Seat. All parts interchangeable. All joints made by metallic contact, thereby obviating the necessity of using jointing material. By removing the cover the seat and valve are withdrawn, enabling new parts to be in- serted in about a minute’s time, and without the neces- sity—as with ordinary valves —of removing the valve body from its fixed position. The Renewable Valve and Seat is made of Hopkinson’s ‘Platnam’' Metal which is suitable for superheated steam and bad waters. There are many valves with renewable valve and seat upon the market, but under modern conditions and high pressures do not last any length of time owing to the deterioration which takes place on the valve and seat, and consequently the renewing of the parts is a frequent occurrence. We have tried our “Platnam” Metal under severe conditions, and, have every confidence in recommending it to work under high temperatures. The “ MAC ” valve has been designed to adopt this metal for the renewable valve and seat. Upward* of 500 ton* of Standard Steel Castings hept in stock. We can give immediate delivery of iron and *teel Valve*. Illustrated Catalogue Post Free on Application. J. HOPKINSON & 0° LD Huddersfield, Makers of Patent Safety Boiler Mounting* and Valve* For High Pressure Superheated Steam, High-class Exhaust and Water Sluice Valves for Condensing Plants, &c.. Automatic Exhaust Valves, Reducing Valves, Steam Traps, &c., &c. Depots & Showrooms—London, Glasgow, Edinburgh, Cardiff, Oldham, Blackpool, Paris & St. Petersburg. No. 275.