In the “United Service Journal,” for June 1833, Mr. Wilkinson gives the following explanation of this curious weapon:
“The Bommarang may be formed of any tough, heavy wood, and is about three-eighths of an inch thick in the middle, gradually tapering off towards the extremities, and rounded on each side from the centre until brought to an edge.
“Construction.—Let A B E be the arc of a circle: the chord A D E = 18 inches: the perpendicular B D = 7 inches: the width B C = 3 inches. Thus constructed, the centre of gravity will fall exactly on the edge of its concave surface at C. When used as an offensive weapon, it is usually thrown with the convex side outwards; but when intended to return, it is held in the reverse position; although it will probably act in either direction, if properly managed.
“For the latter purpose, however, it should be thrown from the hand at a considerable elevation (45°) with a sudden jerk, so as to combine with the projectile force a rapid rotation round its centre of gravity. The rotation acts constantly in opposition to its line of flight; so that if a similar rotation could be communicated without any projectile force, the instrument would move backwards: now, as the force with which it is thrown is constantly diminishing while the rotation continues, it must always arrive at a certain point where these opposite forces balance, or equalize each other. At that moment the weapon would fall towards the ground, were it not for its flat surface and rotatory motion; but in consequence of the centre of gravity being so placed that it will always present its broad surface to the air, it cannot descend perpendicularly, but slides down the inclined plane, up which it has been thrown, in consequence of the whirling motion continuing after the projectile force has ceased; so that if properly thrown, it will pass over the head of the thrower, and often to a considerable distance behind him. On the same principle, a hoop thrown from the hand with a spinning-motion inwards, will begin to return before it touches the ground; and also the curious, though not so familiar instance, of a ball fired from a musket, the barrel of which has been bent to the left, being carried at long distances considerably to the right of the object aimed at, in consequence of the rotation of the ball on its axis, caused by the friction against the right side of the barrel overcoming the projectile force, and thus carrying it across the line of aim.
“The bommarang may be illustrated in a room, by merely cutting a piece of card into the same shape as the diagram; then holding it between the finger and thumb of the left-hand, at an inclination of about 45°, and striking one corner with a piece of wood, it will advance several feet and return to the spot from whence it proceeded. I find, however, that this form is not essential to produce a similar effect, although the most convenient to throw from the hand. Any thin, flat body of a semicircular or rectilinear figure, will return in the same manner, if a rotative motion be communicated to it, in conjunction with the projectile force at a considerable angle of elevation.”
Among this tribe was an old woman in mourning, which was indicated by her face and breast being painted in white stripes with pipe-clay. The people composing the tribe were well-formed, muscular, extremities well-proportioned, but of slender form: the average height five feet five or six inches; cheekbones prominent; nose broad and flattened, with expansive nostrils; mouth large; beard copious, and hair long, black, and coarse; they seem as intelligent, but not so fine a race as the Polynesians, excepting those of the Papuan or Oceanic race, to which they are evidently closely allied. Some physical differences, however, ought to be expected in a people inhabiting so sterile a country, compared with those races inhabiting islands, perhaps as fertile as any in the world. The males of this tribe (similar to other parts of the colony) knock out the front incisor tooth on arriving at the age of puberty, and being admitted into the council and society of men.
I had an opportunity of examining a male stuffed specimen of the “musk duck,” which had lately been shot in the Cudgegong river. I felt desirous of procuring a recent specimen for dissection, to ascertain from what gland the musk was secreted, which diffuses so strong an odour over the body of this bird, and its situation, but did not succeed in securing one fit for the purpose; I felt more desirous of deciding the point, as those persons with whom I had conversed on the subject, and who had seen the bird in its recent state, were much divided in opinion, and gave very contradictory accounts. The bird is of an uniform dark speckled colour over the whole body, except upon the breast and abdomen, where it became lighter; the bill is black and short, in proportion to the size of the bird; the wings are short, and inadequate for the purpose of flight, but assist the animal as it runs over the water; the second penfeather of the wings is the longest; the tail is short, and consists of several very stiff feathers. It is a shy bird, diving the instant it is approached, and afterwards only elevates its head above water to watch proceedings, disappearing again on the least appearance of danger. It requires a good marksman, as well as much caution, to secure a shot even at the small mark the head of this bird presents. The female is said to be smaller than the male.
This estate is used by Mr. Cox principally as a dairy-farm, and a quantity of cheeses are made upon it, about which some of the men were at this time employed. They had now sufficient milk to make four cheeses, and expected soon to increase to ten, daily. Mr. Cox informed me he has made four tons of cheese on this farm in one season, and expected, during the succeeding one, to make nine or ten tons. The price of this article of course varies at Sydney; but it has been sold at forty-six pounds the ton. Attached to the neat little habitation at this farm is a garden, which contains strawberries and gooseberry bushes in a thriving condition, and was rendered gay by many of our European flowering plants in full bloom.
The day after our arrival, (22d,) I ranged about the farm, and was much pleased with its situation. To procure an extensive view, I ascended an elevated hill, distant about a mile from the house, and known by the name of “Mount Brace:” the view from it was extensive, and of much picturesque beauty.—Plains, (varied by wooded patches,) upon which herds of cattle grazed or reposed;—spots of cultivated land, green with the rising grain;—the distance terminating to the horizon in mountains of a greater or less degree of elevation and of varying forms,—peaked, rounded, or tabular, more or less densely wooded; and the Cudgegong river winding its course amidst the tranquil scene, produced, in the combination, a very pleasing landscape. The ascent to “Mount Brace” was rugged, and huge masses of sandstone, in which quartz pebbles were strongly imbedded, projected in several places as if about to be precipitated on the plains beneath; the Liptomera acida, Exocarpus cupressiforme, and the beautiful parasitical Loranthus pended from an Eucalyptus were seen; and other flowering shrubs, among which some small and delicate plants (bearing pink flowers) of the Orchideæ family were also profusely scattered about the declivities. I returned from my walk much gratified with the scenery.