Instructions for use
Select an object to view from the list below. To rotate either click on the rotate icon located in the bottom right hand corner of the image or click and drag within the object window.
Telesonic Lorgnette
Submarine telegraph cable
Cookes portable double-needle telegraph
School telephone
Portable double-needle telegraph, 1850
Box telephone, c.1877
John Gaveys ring transformer
Valve heater transformer
Used by telegraph linemen for sending messages and testing circuits. It is worked by two pairs of press buttons placed at the back of the case. When the instrument is required to work as a galvonometer a lever inside the case withdraws the needle stops, allowing the needles to deflect fully.