N. B. This mixture, when rubbed too much, will be too fierce, and hardly shew any stars at all; and, on the contrary, when not mixed enough, will be too weak, and throw forth an obscure smoke, and lumps of dross, without any stars. The reason of this charge being called the spur-fire, is because the sparks it yields have a great resemblance to the rowel of a spur, from whence it takes it’s name. Characters, or significant Signs, for distinguishing the different Ingredients used in Fireworks. Meal Powder M Corned Powder Э Saltpetre Θ Brimstone Z Crude Sulphur C Z Charcoal C + Sea Coal C S Saw-dust or Beech-raspings B R Steel or Iron-filings S x Brass-dust B x Glass-dust G x Tanners-dust of Bark T x Cast Iron C I Antimony Crude C A Camphor x Yellow Amber A Y Lapis Calaminaris L S Gum ∩. Lamp Black B L Isinglass G I Spirit of Wine W Spirits of Turpentine S T Oil of Spike P O The use of the above characters is, that by the help of them, the different receipts may be contracted to so small a compass, that they may all be contained in one leaf of a pocket book, which is much less than any table that has yet been invented. These signs are also very convenient for those who travel. How to meal GUN-POWDER, BRIMSTONE, and CHARCOAL.