176 PROFESSOR H. B. DIXON ON THE RATE OF EXPLOSION IN GASES. 
(corrected for position) is subtracted from A A', the remainder giving the time of 
explosion, 
I take one example from my note-book of the actual measurements obtained in a 
pair of experiments :— 
ram. 
A.—Distance between “ firing ” and ” second bridge ” marks = 70'5 
Distance between “ firing” and “ first bridge ” marks . = 4’7 
Distance between first and second bridge marks . . . = 65‘8 
At this point on the plate and for this length of swing the distance, which is equal 
to second, is 24‘62 mm. Length of tube between bridges, 75'35 metres. 
Rate of explosion , . . . = 2820 metres per second. 
B, (with connections reversed)— mm. 
Distance between “firing” and “second bridge” marks = 68'6 
Distance between “ firing ” and “ first bridge ” marks . = 2'4 
Distance between first and second bridge marks . . . = 66'2 
At this point on the plate and for this length of swing, the distance, which is equal 
to xoT) second, is 24‘70 mm. 
Rate of explosion . . . . =2811 metres per second. 
Mean rate. =2815 „ ,, 
Fig. 11. 
Ti’aces made by electro-magnetic styli on the moving plate. 
