Dual (pronunced doo-uhl or dyoo-uhl)
(1) Of, relating to, or denoting two.
(2) Composed or consisting of two people, items, parts, etc., together; twofold; double; having a twofold, or double, character or nature.
(3) In the formal grammar of Old English, Old Russian, Arabic and Ancient Greek, denoting a form of a word indicating that exactly two referents are being referred to (a form in the dual, as the Old English git (you two), as opposed to ge (you) referring to three or more.
(4) In mathematics and formal s logic (of structures or expressions) having the property that the interchange of certain pairs of terms, and usually the distribution of negation, yields equivalent structures or expressions
1535–1545: From the Latin duālis (containing two, relating to a pair), the construct being du(o) (two) + -ālis (-al) The Latin duo was from the primitive Indo-European root dwo (two). The General sense of "relating to two, expressing two, composed or consisting of two parts" is from 1650s. Dually is the adverb. The general sense of "division into two" has been in use since 1831. The noun duality (two-fold nature, state of being two or divided in two) is a late fourteenth century form from the Late Latin dualitas.
The noun dualism dates from 1755 as a term in philosophy, the sense being "a way of thinking which explains phenomena by the assumption of two independent and absolute elements," from the French dualisme (1754). The theological adoption to describe the doctrine of “two independent divine beings or eternal principles” was first noted in 1847.
Duel Pronounced doo-uhl or dyoo-uhl)
(1) A prearranged combat between two persons, fought with deadly weapons according to an accepted code of procedure, especially to settle a private quarrel.
(2) Any contest between two persons or entities.
1585–1595: From the earlier English form duell (a single combat (also "a judicial single combat”), from the late thirteenth century Medieval Latin duellum (combat between two persons), a poetical variant of the old Latin form of bellum (war) (related to bellicose), probably maintained and given the sense “duel” by folk etymology with the Latin duo (two). The Old Latin word was retained in poetic and archaic language, the fancied Medieval connection with duo organically creating the linguistic semi-coincidence. In pre-Modern English, the Italian form duello was also used. By the 1610s, the English word had taken on the specialized sense of "premeditated and pre-arranged single combat involving deadly weapons in the presence of at least two witnesses", the general sense of "any contest between two parties" dating from the 1590s. The related verbs are duels, dueling & dueled , dueler & duelist are nouns and duelistic an adjective. The US spelling favors the double “l”.
Dualism in Philosophy
In Metaphysics, dualism holds there are two kinds of reality: the physical world (material) and the spiritual world (immaterial). In the philosophy of mind, Dualism is the position that mind and body are in some categorical way separate and that mental processes and phenomena are, at least in some respects, non-physical. Both positions are radically different from even nuanced flavors of monism (which, at its most pure, maintains there is but the universe and that any form of division of the whole is artificial and arbitrary) and pluralism suggests there are many kinds of substance and not just dualism’s two. In the pre-enlightenment age, dualism had some appeal but it’s now of only historic interest except as a device to train the mind to explore speculative paths.
Dualism in Carburetion
From the late 1950s, Detroit’s V8s, with a sudden and increasing rapidity, grew bigger and more thirsty, the most rapacious of the engines out-pacing the capacity of the carburetors brought from outside suppliers, with the result the only solution was to use two or even three carburettors. The manufacturer did eventually produce units with sufficient throughput but it took a while for supply to meet demand. For street use, triple induction was for some time quite a good solution because the three-in-a-row layout lent itself to a good compromise, the engine most of the time being fed only by the central two-barrel carburetor, the outer two used only when the throttle was pushed wide open. It meant engines with great available power were actually surprisingly economical most of the time although the delicate business of tuning could be a challenge, especially in conditions where there were notable variations in temperature or humidity. For the high performance engines however, the best cost-performance equation (ignoring the fuel consumption which was the customer's problem) was dual induction, two four barrel carburettors, mounted either in-line or side-by side, the air-flow dynamics of the latter delivering the optimal top-end-power.
From its introduction in 1961, the Jaguar E-Type (XK-E for the cars delivered in North America) used triple SU HD.8 carburetors but in 1967, to conform to US emission control rules, the switch for the units delivered there was made to dual Stromberg 175 CD2SEs. Unlike some manufacturers which arranged a separate specification for the US and other markets with more rigorous regulations, Jaguar applied the change to the entire range. Power and torque dropped a bit, especially higher in the rev range, a prelude to the malaise which would affect so many in the 1970s. The changes made by Jaguar to comply with the US regulations were marked by the change in designation from Series I to Series II and the most obvious modifications were (1) the carburetors, (2) the slight truncation of the cigar-shaped tail & the substitution of the elegant tail-lamps with rather more agricultural-looking units, (3) the use of safer, softer rocker switches on the dash instead of the stylish but sharp toggle switches and (4) the deletion of the lovely, fared-in head-lamp covers, the slightly elevated replacements lending the car a slight bug-eyed look. There were a host of other changes, most of which made the Series II a better car but it was just a bit slower and didn't look as good.
The lovely, pure lines of the Jaguar E-Type Series 1 (1961-1968, left). It's not certain Enzo Ferrari (1898-1988) really did say it was "the most beautiful car ever made" but he never denied it and he was a fair judge of such things. The Series 2 cars (1968-1971, right) were a little more cluttered.
However, unlike the US manufacturers (and most of the Germans), even by 1967 there were cottage-industry aspects to some of Jaguar's production facilities and the E-Type changed from Series I to Series II in increments rather than one distinct movements and even then there were inconsistencies and these detail differences intrigue the E-Type cognoscenti, concerned as many are with originality. For this reason, although the factory never used the designations, informally, what are thought “transitional cars” are often referred to as Series 1.25 or 1.5, base on the mix of earlier & later features present, the identification of which is sometime challenging because many later models were modified to make them appear partially or in whole “classic” Series 1 E-Types. The first of the 1.25s are regarded as the models built for US delivery after January 1967 and fitted with the open head-lamps, this change not applied universally until phased in over June-July the same year. The 1.5 designation is used of those built after August-October which in addition to certain detail changes received the dual Stromberg carburetors (if built for delivery to North America) and the rocker switches (the open head-lamps at this point slightly raised by the use of a different assembly) but the “teardrop” tail-lamps above the rear bumpers were retained. Once the revisions were made to the tail and the tail-light, the transition to Series 2 was complete (the Series 2 cars also receiving slightly larger head-lamps). However, in recent years the factory records have been reviewed and it’s clear some of the cars built in 1967 for delivery to North America had the covered head-lamps so these, combined with the Series 1.25 & 1.5 cars modified retrospectively, mean the task of verifying the originality of the later Series 1.X cars can be challenging.
Apparently, at the premiere of Disney’s The Parent Trap (1998), then CEO Michael Eisner (b 1942; chairman and chief executive officer (CEO) of The Walt Disney Company, 1984-2005), believing the central parts in the film had been played by identical twins asked her “Where's your twin?”. She told him she didn’t have one and that she should have been paid double.
