The monument in question is a structure of the type known as a trilithon; that is, it is composed of three large stones, of which two stand upright, while the third rests horizontally on their tops. All three stones are monoliths of hardened coral, rough and much weathered on the surface, and precisely similar to the coral of the neighbouring reefs. Indeed, about halfway between the monument and the beach the coral rock is exposed in a hollow, from which it seems probable that the great blocks were hewn and brought to their present situation. The statement of Mr. Brenchley, that the stone of which the monument consists is not to be found elsewhere on the island, is erroneous. The uprights are quadrangular monoliths neatly squared. No measurements of the stones appear to be on record, but the two uprights are variously estimated to measure from fourteen to sixteen feet in height; their breadth or depth from front to back is variously given as from eight to ten or even twelve feet; but they seem to taper somewhat upwards, for the estimate which assigns twelve feet for the depth of the uprights at their base, mentions seven feet or probably more as their breadth at the top. The thickness of the uprights seems to be four feet. The space between them is variously stated at ten and twelve feet. The cross-stone, which rests on the two uprights, is reported to measure twenty-four feet in length, by four or five feet in depth, and two feet in thickness. Each of the uprights is estimated by Sir Basil Thomson to weigh not less than fifty tons. The tops of both are deeply mortised to receive the cross-stone, the ends of which are sunk into them instead of being laid flat on the top. The cross-stone lies east and west, so that the opening between the uprights faces north and south. On the upper surface of the cross-stone, and at about the middle of it, is a cup-like hollow, very carefully cut, about the size of a coco-nut shell. A large bowl of the same material is said to have formerly stood on the cross-stone, but the statement is not made by an eyewitness and is probably mistaken.[180]

The name which the natives give to this megalithic monument is Haamonga or Ho ha Mo-nga Maui, which is said to mean "Maui's burden." The name is explained by a story that the god or hero Maui brought the massive stones in a gigantic canoe from Uea (Wallis Island), where the great holes in the rock from which he quarried them may still be seen. From the canoe he bore them on his back to the spot where they now stand.[181] This story can hardly be thought to throw much light on the origin of the monument; for the natives are in the habit of referring the marvels which they do not understand to the action of the god or hero Maui, just as the ancient Greeks fathered many natural wonders on the deified hero Hercules.[182] But from Mateialona, Governor of Haapai and cousin of the King of Tonga, Sir Basil Thomson obtained a tradition of the origin of the stones which is at least free from the miraculous element and connects the monument with Tongan history. The account runs thus: "Concerning the Haamonga of Maui, they say forsooth that a Tui Tonga (the sacred line of chiefs), named Tui-ta-tui, erected it, and that he was so named because it was a time of assassination.[183] And they say that he had it built for him to sit upon during the Faikava (ceremony of brewing kava), when the people sat round him in a circle, and that the king so dreaded assassination that he had this lordly seat built for himself that he might sit out of the reach of his people. And this, they say, is the origin of the present custom of the Faikava, it being now forbidden for any one to sit behind the king." At such wassails the presiding chief sits at the apex of an oval. To this tradition Sir Basil Thomson adds: "Mr. Shirley Baker told me that he believed the Haamonga to have been erected as a fakamanatu (memorial) to the son of some Tui Tonga, a view that finds support in the fondness of Tongan chiefs for originality in the burial ceremonies of their near relations—witness Mariner's account of the funeral of Finau's daughter—but on the other hand native traditions generally have a kernel of truth, and the legend of Tui-ta-tui and its consequences finds an analogy in our own custom of guarding against an assassin's dagger at the drinking of the loving cup."[184] The tradition receives some confirmation from the bowl-like hollow on the upper surface of the cross-stone; for the hollow might have served as the king's drinking-cup to hold his kava at the customary wassails. Indeed, Mr. Philip Hervey, the first to examine the monument, describes the hollow in question as "a small cava bowl";[185] and after giving an account of the monument Mr. Brenchley adds: "Its history seems to be entirely unknown, but it is very natural to suppose from its form that it was connected with some ancient kava ceremonies."[186]

The tradition which connects the erection of the monument with the reign of a Tooitonga named Tui-ta-tui is further countenanced, if not confirmed, by a list of the Tooitongas, in which the name of Tui-ta-tui occurs as the eleventh in descent from the great god Tangaloa.[187] This Tui-ta-tui is believed to have reigned in the thirteenth or fourteenth century of our era.[188] From the size and style of the masonry Sir Basil Thomson is disposed to assign the monument to a later date. He points out that for the quarrying and mortising of stones that weigh some fifty tons apiece the craft of stone-cutting must have been fully developed; and from a comparison of the megalithic tombs of the Tooitongas which can be approximately dated, he infers that the craft of stone-cutting in Tonga reached its culmination at the end of the seventeenth century, though it was still practised down to the beginning of the nineteenth century; for Mariner tells us that in his time a professional class of masons was set apart for building the stone sepulchral vaults of chiefs.[189] Yet on the whole Sir Basil Thomson concludes that "when one is left to choose between a definite native tradition on the one hand and probability on the other for the assignment of a date, I would prefer the tradition. If the Tongans had invented the story as a mere expression for antiquity they would not have pitched upon Tui-ta-tui, about whom nothing else is recorded, in preference to Takalaua, Kau-ulu-fonua-fekai, or any of the kings who loom large in traditionary history. Whether the Haamonga was built for a throne or for a memorial, doubtless it is connected with the reign of Tui-ta-tui, who lived in the fourteenth century."[190]

As an alternative to the view that the hollow on the cross-stone was a kava bowl Dr. Rivers suggests that it "may have been destined to receive the skull and other bones of the dead, so often preserved in Polynesia."[191] The suggestion accords well with the opinion that the monument is a memorial of the dead, and it might be supported by the Samoan practice of severing a dead chief's head from his body and burying it separately, to save it from being dug up and desecrated by enemies in time of war.[192] However, Dr. Rivers is careful to add that such a practice is not recorded in Tonga and appears to be incompatible with the mode of sepulture which prevails there.

In this connexion another megalithic monument of the Tonga islands deserves to be considered, though it appears to have been commonly overlooked. It was observed by Captain Cook in the island of Lefooga (Lifuka). He says: "Near the south end of the island, and on the west side, we met with an artificial mount. From the size of some trees that were growing upon it, and from other appearances, I guessed that it had been raised in remote times. I judged it to be about forty feet high; and the diameter of its summit measured fifty feet. At the bottom of this mount stood a stone, which must have been hewn out of coral rock. It was four feet broad, two and a half thick, and fourteen high; and we were told by the natives present, that not above half its length appeared above ground. They called it Tangata Arekee;[193] and said, that it had been set up, and the mount raised, by some of their forefathers, in memory of one of their kings; but how long since, they could not tell."[194]

When we remember that Tongan kings were commonly buried in such mounds as Captain Cook here describes, and further that these mounds were commonly enclosed or faced with great blocks of hewn stone, we may be disposed to accept as reasonable and probable the explanation which the natives gave of this great monolith, which, if the reported measurements of it are correct, must have been no less than twenty-eight feet high. If it was indeed a memorial of a dead king, it might be thought to strengthen the view that the great trilithon was also set up as a monument to a deceased monarch or Tooitonga.

Another possible explanation of the trilithon is, as Sir Basil Thomson points out, that it served as a gateway to some sacred spot inland. But against this view he observes that he examined the bush for some distance in the neighbourhood without finding any trace of ruins or stones of any kind. He adds that the memory of sacred spots dies very hard in Tonga, and that the natives do not believe the trilithon to have been a gateway.[195]

It is natural to compare the trilithon of Tongataboo with the famous trilithons of Stonehenge, which it resembles in plan and to which it is comparable in size. The resemblance struck Dr. Charles Forbes, the first to publish a description of the monument based on personal observation. He says: "The route we pursued led us over a country perfectly level, with the exception of occasional mounds of earth, apparently artificial, and reminding one very much of the barrows of Wilts and Dorset, which idea is still more strongly impressed upon the mind on coming in sight of the monument, which bears a most striking resemblance to the larger gateway-looking stones at Stonehenge."[196] But at the same time, as Dr. Forbes did not fail to note, the Tongan trilithon differs in some respects from those of Stonehenge. In the first place the interval (ten or twelve feet) between the uprights of the Tongan trilithon appears to be much greater than the interval between the uprights of the trilithons at Stonehenge.[197] In the second place, the cross-stone of the Tongan trilithon is mortised much more deeply into the uprights than are the cross-stones at Stonehenge. For whereas at Stonehenge these cross-stones present the appearance of being laid flat on the top of the uprights, the cross-stone of the Tongan trilithon is sunk deeply into the uprights by means of mortises or grooves about two feet wide which are cut into the uprights, so that the top of the cross-stone is nearly flush with their tops, while its ends also are nearly flush with their outside surfaces.[198]

As the origin and purpose of Stonehenge are still unknown, its massive trilithons can hardly be cited to explain the similar monument of Tongataboo. The rival theories which see in Stonehenge a memorial of the dead and a temple of the sun[199] are equally applicable or inapplicable to the Tongan monument. In favour of the mortuary character of this solitary trilithon it might be urged that the Tongans were long accustomed to erect megalithic monuments, though of a different type, at the tombs of their sacred kings, which are situated not many miles away; but against this view it may be argued that there are no traces of burial or graves in the immediate neighbourhood, and that native tradition, not lightly to be set aside, assigns a different origin to the monument. Against the solar interpretation of the trilithon it may be alleged, first, that the monument faces north and south, not east and west, as it might be expected to do if it were a temple of the sun or a gateway leading into such a temple; second, that, while a circle of trilithons, as at Stonehenge, with an opening towards the sunrise may be plausibly interpreted as a temple of the sun, such an interpretation cannot so readily be applied to a solitary trilithon facing north and south; and, third, that no trace of sun-worship has been discovered in the Tonga islands. So far as I have observed, the Tongan pantheon is nowhere said to have included a sun-god, and the Tongans are nowhere reported to have paid any special respect to the sun. Savages in general, it may be added, appear to be very little addicted to sun-worship; it is for the most part among peoples at a much higher level of culture, such as the ancient Egyptians, Babylonians, and Peruvians, that solar worship becomes an important, or even the predominant, feature of the national faith.[200] Perhaps the impulse to it came rather from the meditations of priestly astronomers than from the random fancies of common men. Some depth of thought was needed to detect in the sun the source of all life on earth; the immutable regularity of the great luminary's movements failed to rouse the interest or to excite the fear of the savage, to whom the elements of the unusual, the uncertain, and the terrible are the principal incentives to wonder and awe, and hence to reflexion. We are all naturally more impressed by extraordinary than by ordinary events; the fine edge of the mind is dulled by familiarity in the one case and whetted by curiosity in the other.

Bearing in mind the numerous other stone monuments scattered widely over the islands of the Pacific, from the Carolines to Easter Island, Dr. Guillemard concludes that some race, with a different, if not a higher civilisation preceded the Polynesian race in its present homes, and to this earlier race he would apparently refer the erection of the trilithon in Tongataboo.[201] He may be right. Yet when we consider, first, the native tradition of the setting up of the trilithon by one of the sacred kings of Tonga; second, the practice of the Tongans of building megalithic tombs for these same sacred kings; and, third, the former existence in Tonga of a professional class of masons whose business it was to construct stone vaults for the burial of chiefs,[202] we may hesitate to resort to the hypothesis of an unknown people in order to explain the origin of a monument which the Tongans, as we know them, appear to have been quite capable of building for themselves.