Hotter even than oxyhydrogen is the oxyacetylene flame, which at its hottest point reaches nearly 3500 C.
This differs from the oxyhydrogen blowpipe only in the size of the tubes.
An exceedingly interesting use of the oxyhydrogen flame is in the manufacture of artificial rubies.
It has been used also as a source of heat and light in the oxyhydrogen blowpipe.
Before this was introduced the risk of accident was so great that recourse was seldom had to oxyhydrogen.
Whilst engaged at the Surrey Institution he invented the oxyhydrogen blow-pipe.
The luminous intensity of the oxyhydrogen lime-light as used in practice was generally from 200 to 400 candle-power.
The oxyhydrogen flame has a temperature of about 2000 C., hot enough to melt fire-clay.
To the tail of the arrow is attached a fine rod of quartz which has been melted and drawn out in the oxyhydrogen jet.
While the oxyhydrogen flame is intensely hot, it is almost non-luminous.