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
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.
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.
Next, That the two Eyes were united into one Double Eye, which was placed just in the middle of the Brow, the Nose being wanting, which should have separated them, whereby the two Eye-holes in the Scull were united into one very large round hole, into the midst of which, from the Brain, entred one pretty large Optik Nerve, at the end of which grew a great Double Eye; that is, that Membrane, called Sclerotis, which contained both, was one and the same, but seemed to have a Seam,
by which they were joined, to go quite round it, and the fore or pellucid part was distinctly separated into two Cornea's by a white Seam that divided them. Each Cornea seemed to have its Iris, (or Rain-bow-like Circle) and Apertures or Pupils distinct; and upon opening the Cornea, there was found within it two Balls, or Crystalline Humours, very well shaped; but the other parts of it could not be so well distinguished, because the eye had been much bruised by the handling, and the inner parts confused and dislocated. It had four Eye-browes, placed in the manner exprest in Figure 4. by a a, b b; a a representing the lower, and b b, the upper Eye-lids.