The making of rockets in two parts, the first containing the making of rockets for the meanest capacity, the other to make rockets by a duplicate proposition, to 1000 pound weight or higher / experimentally and mathematically demonstrated, by Robert Anderson.

A second Example, April 21▪ 1692.

I look in Column 2, and find the Re∣quisites of Powder 12 Drams, and 36 Drams; and against these Requisites in the third Column I find 1176 the unequal Range, and 303 the equal Range, which I multiply by 3, and it makes 909.

• 909 The equal Range 2.958564
• 1176 The unequal Range 3.070407
• The Square of 18 half quarters 2.510544
• 2.622387
• 20.47, that is 2 Inches and a half, and 47/100 1.311193

Here may be seen one Example makes the Diameter a little more than two Inches and a half, and in the other a little less, therefore we make the Taper Bores just two Inches and a half for a 6 Inch Rocket. To work from a two Inch and a half Rocket to an Inch, put the unequal Range in the first place, and the Work is done. The Composition these 4 and 6 Inch Rockets were made of, were 1 Sulphur, 1½ Coal, and 4 Saltpetre; but I believe 1 Sulphur, 1 Coal, and 4 Salt∣petre would do better, there being no

great danger of the Rocket breaking, by Reason of the large Diameter of the Bore, and Tapering to a point; and by the same Reason, a lesser solid Head is required, that is about 2 Inches in a 4 Inch, and 1¼ in a 6 or 8 Inch Rocket, will suffice.