10 Dr. Mac Culloch on the 



The next authority is decisive, respecting the rocket, and it is 

 found in a manuscript quoted by Dutens, from which Roger 

 Bacon is supposed to have derived his knowledge of fireworks. 

 The author's name is Marcus Grsecus, and, by the title, the work 

 appears to be a general essay on military pyrotechny. 



" Incipit liber ignium a Marco Gr^eco perscriptus, cujus virtus 

 et efficacia est ad comburendum hostes, tarn in mare quam in 

 terra." The directions for making a rocket are as follows : 

 " Secundus modus, ignis volatilis hoc modo conficitur. R. libras 

 duas sulphuris vivi, libras duas carbonis salicis, salis petrosi 

 libras sex: quse tria subtilissime tereantur in lapide marmoria ; 

 postea pulvis ad libitum in tunica reponatur volatili vel tonitrum 

 facientia. Nota, quod tunica ad volandum debet esse gracilis 

 et longa, et praedicto pulvere optime calcato repleta : tunica vel 

 tonitrum faciens debet esse brevis, grossa, et prsedicto pulvere 

 semiplena et ab utraque parte filo fortissimo bene ligata. Nota, 

 quod in qualibet tunica primum foramen faciendum est, ut tenta 

 imposita accendatur ; quse tenta in extremitatibus fit gracilis, 

 in medio vero lata, et prsedicto pulvere repleta. Nota, quse ad 

 volandum tunica plicaturas ad libitum habere potest, tonitrum 

 vero faciens quam plurimas plicaturas. Nota, quod duplex 

 poteris facere tonitrum, ac duplex volatile instrumentum, vel 

 tunicam subtiliter in tunica includendo." 



There is here no direction, it is true, for boring a rocket, with- 

 out which it cannot fly by its own recoil ; so that it is possible 

 this firework may be a kind of squib, intended to be rendered 

 " volatile" by mechanical means, and not by its own unassisted 

 energy. It is not unlikely that this is the very fire of Joinville ; 

 and the distinction into two parts, the " tunica volatilis," and 

 the " tonitrum faciens," confirms the opinion that these ancient 

 projectiles combined the nature of a shell and a rocket toge- 

 ther. 



It is unnecessary to trace this invention further down. Bacon 

 is the mere copyist of Marcus Graecus, or more probably the 

 recorder of a composition in common use. But the extent of 

 his claims, and of the still worse founded ones of Schwartz, may 

 be suffered to remain for a future notice on gunpowder. 



