The committee reported various devices during several years. William Barton, of Philadelphia, was appointed to submit designs. Sir John Prestwich, an English antiquarian, suggested a design to John Adams in 1779.
Combining the various designs of William Barton and John Prestwich, a seal was adopted on June the 20th, 1782. Arms: Paleways of thirteen pieces argent and gules; a chief azure; the escutcheon on the breast of the American eagle displayed proper, holding in his dextertalon an olive branch and in his sinister a bundle of thirteen arrows; and in his beak a scroll with the motto: E Pluribus Unum. Crest: a glory breaking through a cloud proper and surrounding thirteen stars. Reverse: A pyramid unfinished. In the zenith an eye in a triangle, surrounded with a glory proper, over the eye the words, Annuit Coeptis. Beneath the pyramid, MDCCLXXVI, and the words, Novus Ordo Seculorum. Research Seal of the United States
The Harris Talon Safari is an American bolt-actionhuntingrifle produced in various .30 and .40 Magnum calibres and also .416 Rigbycalibre and takes a 3 to 5 round magazine accordingly. The Harris Talon Safari is made from blued steel with a choice of stocks including glass-fibre, laminate, wood and walnut and has a 25 inch barrel and adjustable folding sights. Research Harris Talon Safari
The Northrop T-38 Talon is an American two-seater supersonic basic/advanced flying trainer aircraft based on the Northrop F-5 fighter, developed during the 1950's, first flown in 1959 and in service since 1961. The Northrop T-38 is a low-wing cantilever monoplane powered by two General Electric J85-GE-5 turbojets providing a top speed of Mach 1.3 and a range of 1385 km typically. Research Northrop T-38
In architecture an arch is a usually curved member made up of separate wedge-shaped solids, with the joints between them disposed in the direction of the radii of the curve; they are used to support the wall or other weight above an opening. In this sense arches are segmental, round (i.e. semicircular), or pointed. A flat arch is a member constructed of stones cut into wedges or other shapes so as to support each other without rising in a curve. Scientifically considered, the arch is a means of spanning an opening by resolving vertical pressure into horizontal or diagonal thrust. The simplest form of an arch is two almost vertical supports lent inwards against one another.
Tile origin of the arch is involved in an obscurity which is never likely to be cleared away, and it is a disputed point where the earliest examples of its use are to be found. Some contend that it was unknown to the Greeks during the best and purest age of their architecture, and was introduced by the Romans, and some ascribe the invention of it to the Etruscans, while others assert that it was known to the ancient Egyptians. But with whatever people the arch may have originated it is certain that the Romans were the first to bring it into general use.
The influence which the arch has had in effecting changes in architecture is much greater than is generally supposed: not only may the vitiation which took place in the Roman be ascribed to it, but even the introduction of Gothicarchitecture, for it gradually encroached upon the leading principle of classical architecture, that the horizontal lines should be dominant, until that principle was entirely abrogated. When first introduced the arch was used quite independent of the columns and their entablature, springing from an impost behind the column, and not reaching high enough to interfere with the entablature, the impost being a few plain mouldings something in the nature of a cornice, and with no resemblance whatever to a capital, At a subsequent period this application of the arch was departed from. In the arch of Hadrian at Athens the arch is still in the same relative position in regard to the columns, but the impost is made into a positive and very rich capital, and the jamb converted into a pier or pilaster with a separate base; the arch also itself rises so high as to cut into the architrave of the entablature although the frieze and cornice are uninterrupted.
At the aqueduct of Hadrian, also at Athens, the arch springs from the architrave of the entablature above the columns and entirely breaks off the continuity of the frieze and cornice, so that the principle of the leading lines being horizontal is entirely destroyed. When once the application of the arch above the columns had been introduced, it appears never to have been abandoned, and the entablature was either broken into angles or altogether interrupted to suit the arch, the principal object aimed at being an appearance of height and spaciousness. In some instances the entablature is omitted entirely, and. the arch rises directly from the capital of the column, as in Gothicarchitecture.
When, after the dominion of the Romans was destroyed, and the rules governing the true proportions of architecture, from which they had themselves so widely departed, were entirely lost, the nations of Europe began again to erect large buildings, they would naturally endeavour to copy the structures of the Romans; but it was not to have been expected, even supposing they were capable of imitating them exactly, that they would have retained the clumsy, and to them unmeaning appendage of a. broken entablature, but would have placed the arch at once on the top of the column, as we know they did; hence arose the various styles which preceded the introduction of the pointed arch, including the Norman. Antiquaries are not agreed upon the origin of the pointed arch, some contending that it is an importation from the east, and others that it is the invention of the countries in which Gothicarchitecture prevailed, and these last are again divided in opinion as to the manner in which it was discovered; but be its origin what it may, the pointed arch was not introduced to general use on this side of Europe until the latter half of the twelfth century. From that time it continued, under various modifications, to be the prevailing form in the countries in which Gothicarchitecture flourished, until the revival of the classical orders: one of the best authenticated instances of the use of the pointed arch in England is the circular part of the; Temple Church of London, which was dedicated in 1185. The choir of CanterburyCathedral, commenced in 1175, is usually referred to as the earliest example in England, and none of earlier date has been authenticated.
The only forms of arch known to have been used by the ancients were the semicircle, the segment, and ellipse, all which continued prevalent until the pointed arch appeared, and even after that period they were occasionally employed in all the styles of Gothicarchitecture. In the Romanesque and Norman styles, the centre, or point from which the curve of the arch is struck, is not infrequently found to be above the line of the impost, and the mouldings between these two levels are either continued vertically (to which arrangement the tern stilted has been applied), or they are slightly inclined inwards, or the curve is prolonged until it meets the impost: these two latter forms arc called horse-shoe arches: pointed arches are sometimes elevated in a similar manner, especially in the Early English style, and are called by the same names but they are principally used in Moorish architecture.
The proportions given to the simple pointed arch (known in French as an ogive) are threefold: the equilateral, which is formed on an equilateral triangle; the lancet, formed on an acute angled triangle, and the drop arch, formed on an obtuse angled triangle; these together with the segmental pointed arch are the prevailing forms used in Early English work although trefoiled arches, cinquefoiled, etc, of various proportions, are frequently met with, especially towards the end of the style, but they are principally used in panellings, niches, and other small openings. Simple pointed arches were used by all the styles of Gothicarchitecture, though not with the same frequency; the lancet arch is common in the Early English, and is sometimes found in the Decorated, but is very rarely met with in the Perpendicular; the drop arch and the equilateral abound in the two first styles, and in the early part of the Perpendicular, but they afterwards in great measure gave way to the four-centred. Plain and pointed segmental arches also are frequently used for windows in the Decorated and Perpendicular styles, but not often for other openings.
With the Decorated style was introduced the ogee arch, or arcade en talon, which continued to be used throughout the Perpendicular style, although less frequently than in the Decorated; it is very common over niches, tombs, and small doorways, and in Northamptonshire in the arches of windows, but difficulty of constructing it securely precluded its general adoption for large openings. About the commencement of the Perpendicular style the four-centred arch appeared as a general form, and continued in use until the revival of classical architecture; when first introduced the proportions were bold and effective, but it was gradually more and more depressed until the whole principle, and almost the top of an arch was lost, for it became so flat as to be frequently cut in a single stone, which was applied as a lintel over the head of an opening. In some instances an arch, having the effect of a four-centred arch, is found, of which the sides are perfectly straight, except at the lower angles next to the impost; it is generally a sign of late and bad work, and prevailed most during the reigns of Henry VIII, Elizabeth I, and James I.
The four-centred arch appears never to have been brought into general use out of England, although the flamboyant style of the continent, which was cotemporary with our Perpendicular, underwent the same gradual debasement; the depressed arches used in flamboyant work are flattened ellipses, or sometimes, as in late Perpendicular, ogees, and not infrequently the head of an opening is made straight, with the angles only rounded off; this last form and the flattened ellipse are very rarely met with in England.
The foregoing enumeration includes all the leading variety of arches, but it must be obvious that many of them may be considerably modified by forming them of different curves. There is also the rampant arch, the imposts of which are at different levels; and what is called a flat arch, which is constructed with stones cut into wedges or other shapes so as to support each other without rising into a curve, and considerable ingenuity is often displayed in the formation of these. Notice must also be taken of a construction which is not infrequently used as a substitute for an arch, especially in the style which is referred to as perhaps being Saxon, and which produces a very similar effect; it consists of two straight stones set upon their edge and leaning against each other at the top, so as to form two sides of a triangle and support a superincumbent weight; excepting in the style just alluded to, these are only used in rough work, or in situations in which they would not be seen, as on the insides of the belfry windows at Goodnestonechurch, near Wingham, Kent.
There is one form given to the heads of openings, which is frequently called an arch, although it is not one. It consists of a straight lintel, supported on a corbel in each jamb, projecting into the opening so as to contract its width; the mouldings, or splay of the jambs and head, being usually continued on the corbels, producing an effect something like a flattened trefoil; the corbels are usually cut into a hollow curve on the under side, but they occasionally vary in form. These heads are most commonly used for doorways: in the southern parts of. the kingdom they are not abundant, and when found are generally of Early English date, but in the north they are much more frequent, and were used to a considerably later period. In France, where the actual openings of the doorways are so constantly made square, while all the leading mouldings are arched, a corbel is very frequently found in a similar situation, which is often ornamented or carvel into a figure. Research Arch
In architecture a talon or ogee is a kind of moulding, concave at the bottom and convex at the top. When the concave part is at the top, it is called an inverted talon. Research Talon
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Seal of the United States
