Tripod

“ Another well-known tripod was the “Plataean,” made from a tenth part of the spoils taken from the Persian army after the battle of Plataea. This consisted of a golden basin, supported by a bronze serpent with three heads (or three serpents intertwined) , with a list of the states that had taken part in the war inscribed on the coils of the serpent. The golden bowl was carried off by the Phocians during the Sacred War ”

“ A few hours after the deposit of the morsel, fresh still and possessing no appreciable smell, up comes the eager picker-up of trifles, scales the stems of the tripod in processions and starts the work of dissection. If the joint suits her, she even goes to live in the sand of the pan and digs herself temporary platforms in order to work the rich find more at her ease. ”

“ The legs of the tripod are spliced to sticks long enough to raise them above the grass: and the topographer, standing sometimes on the body of the buckboard, sometimes on the seat, works with his nose just peering above the giant rushes, from a rod of extra length, deducting from his calculations the height of the tripod and the buckboard from the ground. ”

“ Tripods of bronze, moreover, stood in different parts of the room, and vases of water or wine were placed upon them. Fragments of some of them have been found in the ruins of Nineveh, and they are represented in early Babylonian seals. The feet of the tripod were artistically shaped to resemble the feet of oxen, the clinched human hand, or some similar design. At meals the tripod stood beside the table on which the dishes were laid. Those who eat sat on chairs in the earlier period, but in later times the fashion grew up, for the men at any rate, to recline on a couch. ”

“ That your limbs must labour, while yet ye have strength of your youth for toil.’
With kindly counsel he spake; and they hied them aboard once more,
With intent to get them forth of the mere by toil of the oar.
On sped they with eager purpose: and now did Triton take
On his shoulder the mighty tripod; and now did he enter the lake,
And they saw:—but thereafter did no man mark how he vanished from sight {1590}
With the tripod, anigh though he were. Then each man’s heart grew light,
For that now for their helping had met them one of the Gods ever-blest. ”

“ Midway in the last and furthest of the strips of light, the tripod rose erect on its gaunt black legs, like a monster called to life by the moon—a monster rising through the light, and melting invisibly into the upper shadows of the Hall. ”

“ B, the basal tripod of the Plectoidea, and C, the latticed cephalis of the Cyrtellaria. These three elements are constantly so combined that the primary sagittal ring bisects the cavity of the lattice-shell and produces an external, longitudinal, more or less distinct constriction, separating the lateral inflated halves of the bilocular cephalis; while the three divergent feet of the basal tripod descend from the cortinar or basal plate of the cephalis. The number of the feet is often augmented; they are rarely wanting (probably reduced) . ”

“ They are somewhat awed by the occasion; and when T. produces a tripod and begins to pull out its long legs preparatory to getting a high stand for the camera, they are terrified. The face of the oldest one melts into tears, but we reassure him and the picture promises to be a success. ”

“ It seems to us a thumb-screw at least half an inch in diameter should be used, unless the camera be made to fit into the tripod head, a method often adopted of recent years, and of course the best way of all. On more than one occasion we have nearly lost the camera altogether in the water when trying to screw it to the tripod when working from a boat on a tideway, but by having a part of the base-board made to fit into a wooden tripod head, this at times most difficult operation is rendered easy and certain. ”

“ Reduction of the number of toes on the hind feet to three is common. In some gigantic genera the tail was unusually strong and with the hind limbs formed a tripod support for the animal, which was thus enabled to raise its head to a height sometimes of thirty feet above the ground, and to overlook the vegetation of the marshes in which it wallowed. ”

“ They also frequently had a central upright as support in addition to the three legs. Tripods are frequently 'mentioned in Homer as prizes in athletic games and as complimentary gifts, and in later times, highly decorated and bearing inscriptions, they served the same purpose. ”

“ They were more or less flexible, and when carried in a pack, they could be flattened down like a crush hat, and so took up but little room. If set on the ground when full, they would stand up for a while, but as they soon softened and fell down, they were usually hung up by the bail on a little tripod. ”

“ He stopped a moment and tinkered with the box on the tripod. "Hello!
Hello! Hello! Is that you, O'Connor?" he shouted.
I watched him in amazement. Was the man crazy? Had the blow affected his brain? Here he was, trying to talk into a camera. A little signalling-bell in the box commenced to ring, as if by spirit hands.
"Shut up in that room," growled a voice from outside the door. "By God, they've barricaded the door. Come on, pals, we'll kill the spies."
A smile of triumph lighted up Kennedy's pale face. "It works, it works," he cried as the little bell continued to buzz. " ”

“ This is known to be true of Mexico, and Central and South America. There is no reason why the mound-builders of the Mississippi should not have discovered the use of such a device, readily suggested by the use of supports in building, in baking, or in using the vessels, and it would necessarily follow the modeling of life forms. It is true that quadrupeds would not directly suggest the tripod, but birds [page 412] modeled in clay were made to rest upon the feet and tail, thus giving three supports ”

“ I often find fragments of tripods of terra-cotta with two large handles, of which the three feet as well as the handles have two, three, four, or even five perforations, which can only have served for suspension with a string. On many vases without feet, the rim of the base is perforated on either side as many times as the handles. ”

“ Definition.—Phacodiscida with simple medullary shell, and with three radial spines on the margin of the disk, placed in the equatorial plane.
The genus Triactiscus exhibits on the margin of the lenticular phacoid shell three radial solid spines, the distance between which is sometimes equal, at other times unequal. Either all the three spines are of equal size and similar form, or one odd arm is smaller than the two paired arms. The triradial form of this genus is repeated in Tripodocyclia among the Coccodiscida, and in Tripodictya among the Porodiscida. ”

“ The eyes are marginal and pedunculate. The antennules are imperfectly known, but apparently short, while the antennas are long and slender, with relatively few, long, segments. The mandibles appear to be like endopodites of trilobites and show at least six segments. As so often happens in these specimens from British Columbia, [109] the preservation of the other appendages is unsatisfactory. As illustrated (Walcott, 1912 A, pl. 27, fig. 5) , both endopodites and exopodites appear to be present, and the shaft of the exopodite seems to be segmented as in Triarthrus. ”

“ Modern Apus is certainly much less like a trilobite than has been supposed, and very far from being primitive. The Branchiopoda of the Middle Cambrian could have been derived from the trilobites by the loss of the pleural lobes, the development of the posterior margin of the cephalon to form a carapace, and the loss of the appendages from the abdominal segments. Modern branchiopods can be derived from those of the Middle Cambrian by the modification of the appendages through the reduction of the endopodite and exopodite and the growth of the endites and exites from the proximal segments. ”

“ The exopodites in Triarthrus consist of a proximal shaft, succeeded by numerous short segments, and ending distally in a long, grooved, somewhat spatula-shaped segment. Along the anterior margin of the shaft there are many small spines. Along the posterior margin there are numerous flattened setæ, which all lie in one plane and which seem to be more or less united to one another like the barbs of a feather. The setæ are short, not much longer than the width of one of the thoracic segments, and point backward and outward. ”

“ There are no living trilobites, but the creatures now nearest them are the isopods. The trilobite was more like an isopod in its larva state than like a full-grown one. The trilobite had a hard plate or shell over his head and the front part of his body. This piece of armor was shaped nearly like the large front portion of the shell of a horseshoe [Pg 119] or king-crab. The king-crab uses this shell as a mud-plough to plough its way through the slime, where it finds its food and deposits its eggs. ”

“ The Arthropoda, to make the simplest possible definition, are invertebrate animals with segmented body and appendages. The most primitive arthropod would appear to be one composed of exactly similar segments bearing exactly similar appendages, the segments of the appendages themselves all similar to one another. It is highly improbable that this most primitive arthropod imaginable will ever be found, but after a survey of the whole phylum, it appears that the simpler trilobites approximate it most closely. ”

“ We have in the Trilobites an example of that peculiar, and, as it is sometimes called, rudimentary development of the organs of locomotion in the Class Crustaceans, whereby the legs are made subservient to the double functions of paddles and lungs, The advocate for the theory of the derivation of existing more perfect species, by successive changes from more simple ancient forms, might imagine that he sees in the Trilobite the extinct parent stock from which, by a series of developments, consecutive forms of more perfect Crustaceans may, during the lapse of ages, have been derived ”

“ The two great groups, Annelida and Mollusca, which by their adult structure present considerable affinity with one another, agree in possessing a very similar larval form, known as the trochosphere or trochophore.
A typical trochosphere larva (figs. 1, 2) possesses a small, transparent body divided into a large preoral lobe and a small postoral region. The mouth (4) is on the ventral surface at the junction of the preoral lobe with the hinder part of the body, and there is an anus (7) at the hind end. ”

“ An additional point to be brought forward to show that the trilobites probably pass the greater part of their life on their back, and died in that attitude, is that the young Limulus generally feed while turned on their back; moving at an angle with the bottom, the hind extremity raised, they throw out their feet beyond the anterior edge of the carapace, browsing, as it were, upon what they find in their road, and washing away what they do not want by means of a powerful current produced by their abdominal appendages. ”

“ It had the same place in crustacean development that the opposable thumb is believed to have had in that of man.
An intermediate stage between the Trilobita and the higher Crustacea is at last exhibited to us by the wonderful, but unfortunately rather specialized Marrella, already described. It retains the hypostoma and the undifferentiated biramous appendages of the trilobite, but has uniramous antennæ, there are no endobases on the coxopodites of the thoracic appendages, the pygidium is reduced to a single segment, and the lateral lobes of the thorax are also much reduced. ”

“ In most species, both exopodite and endopodite suffer reduction. The exopodite springs from the basipodite and that segment is closely joined to the coxopodite, producing a protopodite. In some cases the original segments of the endopodites fuse to form a stiff rod. While highly diversified, these appendages are very trilobite-like, and some Ostracoda even have biramous antennæ.
The non-parasitic Copepoda have limbs exceedingly like those of trilobites. Many of them are biramous, the endopodites sometimes retaining the primitive six segments. ”

“ Students of trilobites have always wanted specimens to be delivered to them weathered out of the rock by nature and revealing the ventral anatomy without further work than the collecting, but the wish has never been fulfilled. In the Utica black shales, near Rome, New York, there was finally discovered in 1892 a layer less than ten millimeters thick, bearing hundreds of Triarthrus becki with most of the ventral anatomy intact. ”

“ The appendages, both exopodites and endopodites, are relatively feebly developed as swimming organs. This has been discussed above, and need not be repeated. It must in fairness be observed, however, that many modern Crustacea get about very well with limbs no better adapted for swimming than those of the trilobites.
2. The articulations of the thoracic segments with each other and with the two shields are such as to allow the pygidium to swing through an arc of at least 270, that is, from a position above the body and at right angles to it, around to the plane of the bottom of the cephalon. ”

“ A protopodite is generally formed by the fusion of coxopodite and basipodite, accompanied by a transference of the proximal end of the exopodite to the distal end of the basipodite. A new segment, not known in the trilobites (precoxal) , is sometimes added at the inner end.
Among modern Crustacea, the anterior cephalic appendages and thoracic appendages of the Copepoda and the thoracic appendages of certain Malacostraca, Syncarida especially, are most nearly like those of the trilobite. ”