The Butts formerly in ufe in this kingdom, were generally of earth; but thofe of ftraw are at prefent more in fafhion. The latter kind poffefs an advantage, as they can be moved with eafe to any diftance fixed upon. The manufacture of them is fimilar to that of the common ftraw Bee-hives; and they are ufually made about four feet and an half in diameter, that is, twice the length of the Arrow. The front part is covered with cloth, painted in rings of different colours, in order to mark the refpective degrees of merit each Arrow is entitled to. The way in which this is done, in common, is to divide the length of the Arrow into five equal parts, and taking thefe divifions, as the radii of the different circles. The fifth part of twenty-feven inches, which is the length of the Arrow, is five inches 4-tenths; therefore if one foot of a pair of compaffes be placed in the center of the Target, and a circle defcribed with the diftance five inches 4-tenths, the firft circle will be ten inches 3-fourths diameter. If the foot be extended five inches 4-tenths further, the next will be twenty-one inches 1-half, and fo on with the reft. When all the circles are defcribed, that part inclofed within the circumference of the firft circle, neareft the center, is ufually covered with gold or filver leaf. Between the firft and fecond circle is often a red colour, and the others varied with white, green, &c. according to the tafte of the perfon who makes them. The furface of thefe coloured rings may be again fubdivided into equal parts, by concentric circles at proper diftances from each other. The Target, thus prepared, is fixed on a frame of wood, contrived that it may be elevated or depreffed to any angle of the horizon; as the intended fhots are more or lefs remote.
The Butts ufed by the Archers at Edinburgh are made on a very different principle; I mean thofe intended for fhort lengths. They are of ftraw, laid endways, and preffed hard with a fcrew; after which, the front is cut with a knife, in the manner hay is truffed. Thefe are covered with a little building, to protect the ftraw from injury, and the fhooter from the rays of the fun, while drawing his Bow.
Some time fince, a thought ftruck me, that it would be poffible to contrive a method of difcharging a common gun, by connecting the Target (I mean by the Target, the mark fhot at in fmall diftances) in fuch manner that every time the Arrow pierced it, a difcharge might take place. Accordingly, I contrived and made an apparatus, which fully anfwered what was intended. Since my invention, (as I efteemed it,) I underftand there are Targets fomewhat on the fame plan ufed in Surry; but I have never heard or feen in what manner the machinery is made. What I firft ufed was a fimple gun placed behind the Butt; to the trigger of which was faftened a weight, by a ftring about a foot long. This weight could be put upon a little bracket, under which a bit of wood fupported it. From the Target in front was a wooden rod, moving in a tube through the Butt, and placed in fuch a pofition, that the end came exactly to the foot of the bit of wood fupporting the bracket, having the lead weight on it. When the effect was to be produced, the gun was loaded, and cocked. The weight was placed on the bracket, with the fupport under it. Thus fituated, when the Arrow ftruck the Target, and forced the rod a little backwards, the fupport was difplaed, the bracket fell, and diflodged the weight, which falling, plucked the trigger of the gun, and fired it. The only difficulty I found was in making the Target, and fixing it to the rod which paffed through the Butt. The moft fubftantial way, however, appeared to be that of having a piece of cork cut round, and about three inches in diameter. This was fixed in a tin box, to the bottom of which was a ferrule, wherein the end of the rod was inferted. Cork is the beft fubftance for the above purpofe; becaufe, when the Arrow ftrikes it, it enters, and may be pulled back without injury: but there is nothing elfe I know of, which call be fubftituted, that will not either break the Arrow, or be broken by it. On the front of the cork, a piece of pafteboard may be fixed, to render the mark more conspicuous; and three inches appears a proper fize for the Target, in fhooting the diftance of thirty yards.