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PROFESSOR H. B. DIXOX OX THE MOTEMEXTS 
(1) It starts suddenly, tlirowing back a strongly luminous wave through the 
burning gases and leaving a dark space Avhere it started ; 
(2) It travels with constant velocity, unless it traverses a junction not rigidl}" 
attached ; after being damped down by such an obstacle, it recoups itself 
and again starts with abruptness ; 
(3) On collision with a similar detonation-wave moving in the opposite direction, 
or with a rigid diaphragm, it sends back a reflected wave not so rapid as 
itself, and as a rule not so luminous. 
In tlie case of the more luminous explosions, e.y., those of cyanogen, acetylene, and 
carbon disulphide mixtures, the reflected waves were less luminous than the 
detonation-wave ; but in the case of the less luminous explosions, e.g., those of 
Iiydrogen and carbonic oxide, which depend largely for their light on the particles 
detached from the tubes, the waves reflected from a collision were sometimes more 
luminous than the detonation-waves themselves, for instance in fig. 42. 
Witli regard to the pressures produced in the detonation-wave, our experiments 
have repeatedly shown that glass tubes more readily fracture at the point of collision 
of two detonation-waves than when the detonation-wave traverses the tube in one 
direction onl^n"^ A tube has stood half-a-dozen passages of the detonation-wave in 
one direction, and has been shattered by the first collision. A closed tube breaks 
most frecpiently at the end furthest from the firing point. Again, the point at which 
the detonation-wave is set-uj) (and at which the corresponding “ retonation-wave ” is 
driven backwards) is frerpiently found to be the place where the tube is broken. Of 
course with a weak tube tins would mean nothing but that the tube would be 
fractured by the detonation, as it would naturally break at the point where the 
fracturing force was first applied. But we have found that strong tubes have 
withstood the passage of the detonation-wave which was already determined before 
entering tlie tube, and have been fractured when the detonation-wave was started in 
the tul)e itself Again, the tube has bioken at the point where the detonation began, 
and has for the rest of its length withstood the passage of the detonation (as shown 
photographically), t 
In 189i I Avas unable to show this experimentally (‘Manch. IMeinoirs,’ lY., S, p. ISO). In the 
experiments then made the flame was not photographed, and it is possible that the explosions were 
damped down at the junctions. 
t Messrs. Jones and Bower have made many attempts to obtain quantitative measurements of the 
pressures produced in the detonation of gaseous mixtures by the method of fracture of glass tubes, but 
the results cannot be regarded as certain. They found for the detonation of the mixture CoXo-l-Oo a 
pressure between 58 and 75 ats., Avhile Dr. Cain and 1 found for the same detonation a pressure between 
60 and 140 ats. For the mixture CbXo + Oo + SXo, Messrs. JoNES and Boaver found the pressure betAveen 
74 and 9.3 ats., AA'hile Ih’. Cain and I found it betAveen 63 and 84 ats. Cf. ‘Manch. Memoirs,’ 1894 
lY., 8, p. 174, and 1898, Xo. 7. 
