128 Br. Cutbush on the Chinese Fire, &c. 
Another, for gerbes of ten and eleven twelfths, and one neh 
calibre. 
Nitrate of potash tres anebotirs I oz. 
Sulphur - 
i - - - Ido. 
Meal powder - - - - 8 do. 
Charcoal - - - - Ido. 
Puly. Cast iron - - - -« > 8do. 
stances is various, viz. to meal powder as one to five, one 
to ten, &e. In one formula the proportion is still greater, 
and in another less ; but by mixing seven and a half ounces 
of steel dust with meal powder, salt petre, and sulphur, in the 
proportion of eleven pounds, one pound two ounces, and four 
ounces respectively, is the best calculated to produce the or- 
dinary brilliant fire. . 
With respect to what is denominated fire jets, or fire 
spouts, we may add that they are similar. They are cases 
eharged solid with particular compositions. These jets are 
made with a calibre of one third of an inch, to one and one 
third of an inch in interior diameter. They are seven ot 
eight exterior diameters in length, and are charged with the 
particular composition, driving each charge with twenty 
blows of a small mallet. The first charge is the ordinary 
fire composition. Fire jets are calculated for turning, as 
well as for fixed pieces. 
Common fire for calibres of one third of an inch. 
Meal powder -.-+, - so 
Charcoal ee 3 do. 
Common fire for calibres of five twelfths to half an inch. 
* Mealpowder - - - ~ 602. 
Charcoal... ions ae? 3 do, 4 dr. 
Common fire for calibres above half an inch. 
Mealpowder - - - - 160%. 
Charcoal - - ~ - 4 do. 
