STERLING TELEPHONE AND ELECTRIC Co. Ltd
GAS AND WATERTIGHT MAGNETO MINING TELEPHONE
Note: This Telephone complies with Home Office requirements
No. U 563
Mining Telephone, Magneto Ringing. Watertight. Flame Proof. In Last Iron Case, and comprising an Inner and an Outer Compartment, both fitted with Heavy water tight Doors. The Inner Compartment contains Powerful 5 Magnet Generator, 1,000 ohm Polarised Call Bell of special design, Induction Coil, Switch-springs. Shelf and Clips to hold Two Celevox Dry Cells, and Terminals for Extension Bell. This Compartment need not be opened except for inspection or adjustment. The Outer Compartment contains Two Double Pole Receivers fitted on flexible Phosphor Bronze arms, Solid Back Transmitter, and Generator Handle. The Case is quite Watertight and is fitted with a strong Malleable Iron Handle. Every part employed in this Instrument is specially treated in order that it may be suitable for the conditions under which it is required to work. Special provision to prevent corrosion and to absorb moisture.
Note: The Generator of the above Instrument is provided with Totally-Enclosed Cut-out Contacts, thus rendering it impossible for open sparking to take place in a gaseous atmosphere. even though explosive gas may have found its way into the interior of the Telephone.
Last revised: April 28, 2021