Then this _Wedge_, being first thrust into the Hole with the _Cartridge_, the round side, whether the Priming-hole is, being uppermost, the other _Wedge_ is to be thrust in, home to the due position, care being taken, that they fit the Hole in the Rock as exactly as may be. Then the end of the lower _Wedge_ being about an Inch longer, than that of the upper outwardly, and flatned, priming Powder is to be laid upon it; and a piece of burning _Match_ or _Thread_ dipt in _Brimstone_ or other such prepared combustible Matter, fastned to it, that may burn so long before it fire the Powder, as he, that orders it, may have time enough to retire quite out the Pit or _Adit_, having first placed a piece of Wood or Iron so, as one end thereof, being set against the end of the lower Wedge, and the other against the side-wall, so as it cannot slip. Which being done, and the Man retired, when the Powder comes to take fire, it will first drive out the uppermost Wedge, as far as it will go, but the slaunting figure of it being so made, as the farther it goes backward, the thicker it grows, till at the last it can go no farther, then the {85} fire tears the Rock to get forth, and so cracks and breaks it all about, that at one time a vast deal of it will either be quite blown out, or so crackt and broken, as will make it easie to be remov'd: And according to the effect of one such _Cartridge_, more may be afterwards made use of, as hath been said. * * * * * _Observables upon a _Monstrous Head_._ [Illustration] This was the Head of a _Colt_, represented in the annexed _Figure_ 4. first viewed by Mr. _Boyle_, who went into the Stable where the _Colt_ lay, and got the Head hastily and rudely cut off, the _Body_ thereof appearing to his Eye compleately formed, without any _Monstrosity_ to be taken notice of in it. Afterwards he caused it to be put into a Vessel, and covered with _Spirit of Wine_ thereby chiefly intending, to give good example, together with a proof, that by the help of the said _Spirit_, (which he hath recommended for such Properties in one of his _Essays_ of the _Usefulness_ of _Natural Philosophy_) the parts of _Animals_, and even _Monsters_, may in _Summer_ it self be preserved long enough to afford _Anatomists_ the opportunities of examining them. The Head being opened, and examined, it was found. _First_, That it had no sign of any _Nose_ in the usual place, nor had it any, in any other place of the Head, unless the double Bag CC, that grew out of the midst of the forehead, were some rudiment of it.