Tuesday’s secondhand market turned up something I have secretly wanted for a long time- an Aldis lamp. The Aldis lamp is a handheld lamp with a trigger mechanism allowing pulses of light to be modulated to send messages using Morse code. These communications are pretty secure as only those on a line of sight can see them and are still used today in periods of radio silence. Speeds of up to fourteen words a minute can be achieved by skilled operators. This Aldis lamp dates from the Second World War:As can be seen the lamp is made up of three main parts, the body of the lamp holding the bulb and reflector:The handle, with the trigger mechanism:And a simple optical sight allowing it to be aimed at the receiving signaller:The front plate of the lamp is removable to allow the bulb to be replaced and to let the operator fit coloured lenses if required:Power to the lamp is fed in through a long cable at the bottom of the handle which has two terminals on the end to plug into ship or aircraft 12V electrical systems:As can be seen, as is often the case, the terminals have been replaced with crocodile clips allowing the lamp to be used with a battery. This lamp is an Air Ministry example and the maker’s plate indicates it was manufactured in 1942 by The Pullin Optical Company Ltd:The Aldis lamp fits snuggly inside a sturdy wooden box, with felt to help cushion it:The box again has the Air Ministry logo stamped on the side:The lamp was generally held in the crook of the arm or with the spare hand steadying it when signalling, as in this case aboard a Short Sunderland flying boat:A quick search on eBay shows that these lamps are still out there and should not be too hard to find if you want one, however many are RN or post war examples so check listings carefully!