In the 1933 Mullard data book it is referenced as a general purpose valve for replacement use only and was sold for 13/6.
The dome of the gold metallised valve contains the printed identification and details of the maximum anode voltage.
Here is another 244V with an interesting warning label. It reads: This valve has the metal coating connected to the centre pin. This coating should NOT come in contact with any earthed screens, etc., in the receiver, as this would result in short circuiting of the biasing resistance or battery.
The balloon envelope is 46 mm in diameter, and excluding the B5 base pins is 94 mm tall.
References: Datasheet, 4023 & 1043. Type 244V was first introduced in 1930.