Telegraph Key

I found this on a window sill in an old barn. I can't even guess how long it's been there.  It's obviously missing a couple parts. It is a "straight-key" type telegraph key.  It consists of a simple bar with a knob on top and a contact underneath. When you toggle the knob down, it compresses the spring connecting a circuit allowing electricity to flow. When you release the spring expands lifting the lever back up interrupting the circuit.It probably looked something like this when it was new.

This is the key you see in all the movies. They never use it right though. You'll see actors often tapping it with one or two fingertips. The correct technique is to grasp the knob with the thumb and two fingers to reduce the motion of the fingers. The wrist and forearm should direct the motion. John Shannon (K3WWP) hasa great article on that here.

It's very similar to the J-37 Key and the J-38 Key. I brushed off some of the dust and found a few markings. There is a "US" in pink ink (possibly faded red) with an anchor between indicating it's a naval design. To the right of the paddle and in white is the text "CJB 26021." The CJB means it was manufactured by the J. H. Bunnell Company in New York. 26021 is a model number that dates it to after 1918. These markings match the company name directly below the adjusting screw. It is a standard legless pattern key that first appears in catalogs around 1880. The lever is steel and (not brass) and the knob is plastic. It might actually be kind of rare.