"One pound of sulphur vivum, two pounds of charcoal of linden wood or of
willow, six pounds of saltpetre, which three things are minutely pounded
in a marble mortar. After that you will charge with it a sheath suitable
for flying, or for making thunder.
"Note. The sheath for flying ought to be slender and long, and filled
with the aforesaid powder well rammed.
"The sheath for making thunder ought to be short and large, and half
filled with the aforesaid powder, and well bound in every direction with
an iron band.
"Note. That in every sheath a small aperture is to be made, in order
that it may be ignited by the match when applied, which match is made
slender at the extremities, but in the middle large and filled with the
aforesaid powder."