Fire ball, incendiary dart, viola organista and clock springs
Recipes for an incendiary bombard ball and fire dart, the viola organista bow gearing, and a list of ancient engineers
A dense working page mixes incendiary weapons, clockwork and a memorandum. Two recipes give an incendiary ball for a bombard, made of tow soaked in pitch, turpentine and linseed oil and stuffed with powder-charged hemp, and a fire dart for a great bench crossbow whose horns catch fire on impact so the flame is not blown out in flight. A left column details the gearing of the bow of the viola organista, marked f and a b, and a stack of four conical springs that hand off motion to keep a clock turning evenly. A right column lists ancient engineers, and a small sphere with tiny figures at its equator is sketched at the centre.
On this page
Recipe for an incendiary bombard ball
Tow soaked in pitch, turpentine and linseed oil is wound into a ball and wrapped with turpentine-dipped hemp. Four to six arm-thick holes are bored and packed with loose hemp, turpentine and gunpowder before the ball is loaded into the bombard.
Fire dart for a bench crossbow, lit on impact
A dart shot from a great bench crossbow carries fire in linen within two horns. When the point drives in, the horns press together and ignite powder and pitched tow. Good against ships and wooden bastions, it must catch only after the blow, or the wind puts the flame out in flight.
Gearing of the viola organista bow (f, a b)
A detail shows how the bow of the viola organista is driven. If the teeth of the two-tempo wheels differ by a set number and do not meet together, as at a b, the bow moves evenly; otherwise it jerks. Done this way, the little wheel f always runs smoothly.
Four conical springs for a clock's uniform motion
A stack of four springs drives a clock so that as one finishes its course the next begins. While the first turns, the second stays still and the first screws onto it; once fully wound in, the second takes up the same motion, and so on through all four.
List of ancient engineers
A right-hand column heads 'Names of engineers' and lists Callias of Rhodes, Epimachus the Athenian, Diogenes the philosopher of Rhodes, Chalcedonius of Thrace, Phebar of Tyre, and Callimachus the architect, master of fires.