Knapsack searchlight

A searchlight which can be carried in a soldier's knapsack has been invented and has already been adopted by at least two Governments, says the "Observer."
The contrivance consistes of a portable searchlight apparatus of such power and lightness that a beam of 600,000 candle-power can be developed with an outfit weighing no more than 35lbs.
The principle is one of a combination of two gases, which, acting on a new metallic pencil, produce by combustion a light of extreme brilliance.
It is claimed that the light developed is so powerful that it can be used for heliographing over long distances by daylight when there is no sun. By night it is said to have an effective range of more than 30 miles.
The German and Greek Governments have already ordered a large number of outfits; the British authorities are carrying out experiments with the appliance, and the United States Government has also taken it up.

Eastern Province Herald - November 12, 1908

I wonder what the "pencil" consisted of. Possibly this is the invention of the arc light.