Tuesday, February 18, 2020

Herringbone

Herringbone (pronounced her-ing-bohn)

(1) A pattern, the weave resembling the skeleton of a herring fish, consisting of adjoining vertical rows of slanting lines, any two contiguous lines forming either a V or an inverted V, used in masonry, textiles, embroidery etc and .  Also called chevron, chevron weave, herringbone weave; a type of twill weave having this pattern.

(2) A fabric constructed with this weave.

(3) A garment made from such a fabric, applied especially to jackets and coats.

(4) In skiing, a method of going up a slope in which a skier sets the skis in a form resembling a V, and, placing weight on the inside edges, advances the skis by turns using the poles from behind for push and support.

(5) A type of cirrocumulus cloud.

1645–1655: The construct was herring + bone.  Herring was from the Middle English hering, from the Old English hǣring, from the Proto-West Germanic hāring (herring) of unknown origin but it may be related to the Proto-Germanic hērą (hair) due to the similarity of the fish’s fine bones to hair. It was cognate with the Scots hering & haring, the Saterland Frisian Hiering & Häiring, the West Frisian hjerring, the Dutch haring, the German and Low German Hereng & Hering, the French hareng, the Norman ĥéren and the Latin haringus; all borrowings from the Germanic.  Bone is from the Middle English bon, from the Old English bān (bone, tusk; bone of a limb), from the Proto-Germanic bainą (bone), from bainaz (straight), from the primitive Indo-European bheyhz (to hit, strike, beat).  It was cognate with the Scots bane, been, bean, bein & bain (bone), the North Frisian bien (bone), the West Frisian bien (bone), the Dutch been (bone; leg), the Low German Been & Bein (bone), the German Bein (leg), the German Gebein (bones), the Swedish ben (bone; leg), the Norwegian and Icelandic bein (bone), the Breton benañ (to cut, hew), the Latin perfinēs (break through, break into pieces, shatter) and the Avestan byente (they fight, hit). It was related also to the Old Norse beinn (straight, right, favorable, advantageous, convenient, friendly, fair, keen) (from which Middle English gained bain, bayne, bayn & beyn (direct, prompt), the Scots bein & bien (in good condition, pleasant, well-to-do, cozy, well-stocked, pleasant, keen), the Icelandic beinn (straight, direct, hospitable) and the Norwegian bein (straight, direct, easy to deal with).  The use to describe a type of cirrocumulus cloud dates from 1903.  The alternative form is herring-bone (not herring bone which would be a bone of a herring).

The herringbone shape (left) and a herring's bones (right).

The herringbone pattern picked up its rather fanciful name because of a resemblance to the fine bones of the fish.  First used in masonry, the motif has for centuries been used in wallpaper, mosaics, upholstery, fabrics, clothing and jewellery.  In engineering, the pattern is found also in the shape cut for some gears but this functionally deterministic.

Roman herringbone brickwork, Villa Rustica, Mehring, Trier-Saarburg, Rhineland, Germany.

The original herringbone design was a type of masonry construction (called opus spicatum, literally "spiked work”) used first in Ancient Rome, widely adopting during medieval times and especially associated with Gothic Revival architecture; it’s commonly seen today.  It's defined by bricks, tiles or cut stone laid in a herringbone pattern and is a happy coincidence of style and structural integrity.  Although most associated with decorative use, in many cases the layout was an engineering necessity because if tiles or bricks are laid in straight lines, the structure is inherently weak whereas if built using oblique angles, under compression, loads are more evenly distributed.  One of the reasons so much has survived from antiquity is the longevity of the famously sticky Roman concrete, the durability thought in part due to chemical reactions with an unusual Roman ingredient: volcanic ash.

1973 Holden Monaro GTS (253) with Herringbone cloth inserts (left) and replica fabric now available from Global Trim (right).  In 1973, Holden replaced the previous houndstooth cloth insert option with one in a herringbone pattern (Ranier, option code 30Y), the most popular combination early in the availability being 1854-30Y (black vinyl + herringbone cloth inserts); the factory code for an all vinyl interior in black was 1854-30X.  At the time, option 30Y listed at Aus$75.00 (4 seats) and Global Trim's replica fabric is Aus$330 per metre (the bolts 1.5m wide); to re-trim an interior demands 2m. 

Lindsay Lohan in herringbone flat-cap.

Of gears

Although the term “herringbone cut gears” is more poetic, to engineers they’re known as double helical gears.  In both their manufacturing and operation they do present challenges, the tooling needed in their production demanding unusually fine tolerances and in use a higher degree of alignment must be guaranteed during installation.  Additionally, depending on use, there is sometimes the need periodically to make adjustments for backlash (although in certain (usually lower-speed) applications they can be designed to minimize this).  However, because of the advantages the herringbone structure offers over straight cut, spur or helical gears, the drawbacks can be considered an acceptable trade-off, the principle benefits being:

(1) Smoothness of operation and inherently lower vibration:  The herringbone shape inherently balances the load on the teeth, reducing vibration and generated noise.

(2) A high specific load capacity: The symmetrical design of herringbone gears offers a high surface area and an even distribution of load, meaning larger and more robust teeth may be used, making the design idea for transmitting high torque or power.

(3) A reduction in axial thrust: Probably the reasons engineers so favour the herringbone is that axial thrust can be reduced (in certain cases to the point of effective elimination).  With helical gears, the axial force imposed inherently acts to force gears apart whereas the herringbone gears have two helical sections facing each other, the interaction cancelling the axial thrust, vastly improving mechanical stability.

(4) Self-regulating tolerance for misalignment. Herringbone handle small variations in alignment better than spur gears or single helical gears, the opposing helix angles assisting in compensating for any axial misalignment, contributing to smoother gear meshing and extending the life of components.

(5) Heat dissipation qualities: The symmetrical structure assists heat dissipation because the opposing helices create a distribution of heat through a process called mutual heat-soak, reducing the risk of localized overheating, something which improves thermal efficiency by making the heat distribution pattern more uniform.

Gears: helical (left), herringbone (or double helical) (centre) and straight-cut (right).  Although road cars long ago abandoned them, straight-cut gears are still used in motorsport where drivers put up with their inherent whine and learn the techniques needed to handle the shifting.

Monday, February 17, 2020

Monsoon

Monsoon (pronounced mon-soon)

(1) The seasonal wind of the Indian Ocean and southern Asia, blowing from the southwest in summer (associated with heavy rain) and from the northeast in winter.

(2) On the Indian sub-continent and in nearby countries, the season during which the southwest monsoon blows, commonly marked by heavy rains; the rainy season (known as the Asiatic monsoon).

(3) Any wind that changes directions with the seasons (rare) or any persistent wind established between water and adjoining land.

(4) In colloquial use, sudden, hard rain.

(5) Entire meteorological systems with such characteristics.

1547: From the Raj-era English monsoon (alternating trade wind of the Indian Ocean), from the now obsolete Dutch monssoen, from the Portuguese monção, from the earlier moução, from the Arabic موسم (mawsim) (time of year, appropriate season (for a voyage, pilgrimage etc.)), from وَسَمَ‎ (wasama) (to mark, to brand; he marked).  Monsoon has a specific technical meaning in meteorology but in casual use it’s sometimes used as a synonym for (especially sudden) hard rain as an alternative to terms like deluge, rainstorm, storm & squall.  Monsoon is a noun and monsoonal & monsoonish are adjectives; the noun plural is monsoons.

Lindsay Lohan caught in a monsoon in Confessions of a Teenage Drama Queen (2004).

The Arabic word came into use among Portuguese sailors crewing ships which plied the Indian Ocean trade routes.  In the Arabic, mawsim could be used to describe anything recurrent, especially annual events such as festivals and, confusingly to the Portuguese, it could reference difference seasons (spring, summer etc) because each could be associated with the appropriate time for some activity (a pilgrimage, a harvest et al).  Under the Raj, in the sub-continent and adjacent lands, it came to be applied specifically to the seasonal (April through October) south-westerly winds which both brought the rains and were best suited to the sailing ships making voyages to the East Indies (modern-day Indonesia).  Technically, the winter’s north-easterly winds were also a monsoon but because the summer monsoon generated much heavier rain, it came emphatically to be spoken of as "the monsoon".  Because of the similarity of the conditions, use of the word (as a technical term) has extended from the original (Asian-Australian) to describe the rain patterns in West Africa and the Americas associated with seasonal changes in the direction of prevailing winds but, because the change is not as dramatic (especially in North & South America), some meteorologists prefer other terms.

To a meteorologist a monsoon is not just the summer rains but a system of winds which influences the climate of a large area which stretches as far south as northern Australia, the prevailing direction reversing with the change in seasons.  Although affected by ocean temperatures, monsoons were long thought primarily caused by the much greater annual variation in temperature over large land masses but the influence of oceanic temperatures is now becoming clear.  This variation induces higher atmospheric pressure over the continents in the winter and much lower levels in summer, the disparity causing the strong winds to blow between the ocean and the land, accounting for the heavy seasonal rainfall.

Monsoon storm event over Tuscon, Arizona.

That climate change is caused by the increased levels of atmospheric CO2 is now accepted by just about everybody except some right-wing fanatics and those who get their medical and scientific advice from their hairdressers or personal trainer.  In the last decade, enough data has been accumulated to build models which predict the changes the Asian-Australian monsoon is expected to undergo and although there are variations between them, all seem to suggest a net increase in monsoon rainfall on a seasonal mean, area-average basis, the causes essentially two-fold: The rise in the land-sea thermal contrast and, of greater significance, warming over the Indian Ocean which means the monsoon winds will carry more moisture to the sub-continent.  There are variations in estimates but typically most models suggest the increase in total rainfall over India will be around 5-10%.  That figure is often misunderstood because it refers to a long-term average number and given that in some years rainfall will actually be below average, in some years it will be much above and climate simulations also show different patterns of geographic distribution which means it’s difficult to predict specific outcomes except to say the trend-lines are upward.  The effect on the Asian-Australian monsoon of anthropogenic climate change is thus certain in direction (and to a degree in extent) but unpredictable at the margins.  The mechanism is well known:  A warming climate allows more moisture to be held in the atmosphere which means rainfall when it does occur will be heavier.  Carbon is a form of energy so more of it in the atmosphere means a more energetic atmosphere and thus climate events, when they occur, will probably tend to the extreme in frequency and severity.

Sunday, February 16, 2020

Solvent

Solvent (pronounced sol-vuhnt)

(1) Able to pay all just debts; meet all financial obligations (ie not insolvent).

(2) Something with the power of dissolving.

(3) A usually liquid substance that dissolves another to form a solution.

(4) Something that solves or explains (archaic).

1620–1630:  From the Middle English solvent, from the French, from the earlier form solver.  Latin root was solventem, accusative singular of solvēns (releasing), present participle of solvō, derived from the construct se (away) + luō (to untie, set free, separate), most usually as solvere (to loosen, to free).  The meaning as applied to financial debts, originally a French form, dates from the 1650s.  As a substance able to dissolve other compounds, use emerged in the 1670s.  Unfortunately, the Czech noun solvence (solvency) was never picked up by English; its adoption would have made the odd clumsy phrase more elegent.  Solvent & insolvent are nouns & adjectives and solvency & insolvency are nouns; the noun plural is solvents.

Solvents and exfoliants.

Although the end result of use should (helpfully) be similar, technically, solvents and exfoliants differ both  in composition and application.  A solvent is a substance capable of dissolving other substances, typically for the purpose of removing them from the surface to which they've become adhered although in science and industry, they're used also for dilution or extraction and in all but some specialized products, they tend to be liquids, whether used in cleaning, manufacturing or chemical processing.  The concoctions are many but the best known solvents include water, alcohol and the acetone familiar to users of nail-polish removers.  Exfoliants are best-known as the commercially packaged substances used to remove dead skin cells on the face, the hope being an improvement in the texture of the skin and thus a more glowing, youthful appearance.  Unlike solvents which dissolve stuff, exfoliants work by the mechanical-chemical process of physically scrubbing or sloughing off the outermost layer of dead skin cells and are packaged variously as scrubs with abrasive particles, brushes, loofahs, or chemical mixes such as alpha hydroxy acids (AHAs) or beta hydroxy acids (BHAs).

In praise of Orange Solv.

Orange Solv is a water-soluble solvent marketed as an alternative to the petroleum, chlorinated or glycol-ether mixtures used in heavy duty cleaning and de-greasing.  Applications include grease and tar removal from engines and parts, paint removal from solvent-resistant hard surfaces and it’s widely used commercially to remove chewing gum and stains from industrial carpets.  It’s been adopted by local governments as an additive to high-pressure water systems in the removal of graffiti and one vlogger (influenced presumably by practical experience) endorsed Orange Solve as the preferred solvent to remove the CHEATER signs spray-painted onto cars by vengeful WAGs.  Orange Solve is made from D-Limonene, an extract from the peel of oranges and lemons.  Low in toxicity, it’s pleasant to use, has minimal skin impact and is biodegradable.  Produced using the waste from the citrus industry, it's classified as non-flammable and when diluted with equal parts water, pH is a mildly alkaline 9. After use, there remains a citrus fragrance wafting about which some enjoy and others find intrusive.

Saturday, February 15, 2020

Vantablack

Vantablack (pronounced van-tah-blak)

(1) A black material which absorbs 99.965% of light reaching its surface.

(2) A shade of black of extraordinary blackness.

(3) Used loosely, of or pertaining to something very black.   

2014: A coining in Modern English, the construct being Vanta (the acronym for Vertically Aligned NanoTube Arrays) + black.  Black (in the sense of the color (absorbing all light and reflecting none; dark and hueless)) was from the Middle English blak, black & blake, from the Old English blæc (black, dark (also “ink”), from the Proto-West Germanic blak, from the Proto-Germanic blakaz (burnt).  Related were the Dutch blaken (to burn), the Low German blak & black (blackness, black paint (black) ink) and the Old High German blah (black), possibly from the primitive Indo-European bhleg- (to burn, shine).

Vantablack is built from clusters of vertical nanotubes on a substrate using a modified chemical vapour deposition process (CVD).  When light strikes Vantablack, instead of reflecting back and thus being visible, it becomes trapped, bouncing among the tubes until absorbed, dissipating into heat.  The densities are impressive for physical stuff; each square centimetre contains about a billion nanotubes.  Industrially, it’s an improvement over previous products because it can be created at 750°f (400°c) whereas an earlier substance, developed by NASA, demanded a 1380°f (750°c) environment.  However, in manufacturing, this is expensive and, Vantablack can be grown only on materials capable of enduring this temperature, further limiting commercial application.  Despite this Vantablack is a functional improvement which also offers better thermal stability and a greater resistance to mechanical vibration.  First developed in the UK’s National Physical Laboratory, trademark is held by Surrey NanoSystems.  The blackest known material ever in earthly existence, Vantablack is used to improve the performance of both ground and space-based cameras, improve heat-absorption in solar arrays and prevent stray light entering telescopes.  The military apply it to thermal camouflage because if used to coat 3D objects, they appear visually flat “black holes” without any shape or depth.

Potential LVBD customer.  Lindsay Lohan and the quest for the perfect LBD.

Surrey Nanosystems in 2016 granted Sir Anish Kapoor (an Indian-born UK British sculptor), the sole licence exclusively to use Vantablack for all “artistic purposes”, meaning no other artist could produce work using the material.  The exclusivity clause attracted much criticism from other artists who claimed it was absurd to suggest an individual could enjoy sole rights to a color.  While that might have been the consequence, what Surry did was licence the use of a commercial product for certain limited purposes, something hardly unusual in industry.  What triggered the controversy was that it involved restricted artists producing their product for some commercial gain; there is nothing to prevent anyone creating an artwork using Vantablack; it just can’t be exhibited or sold and must exist only for personal enjoyment.  Some artists actually responded by producing and trade-making certain products and making them freely available to any artist except Sir Anish; he was banned.  Legal commentators and philosophers have about the written about what is clearly a restraint of trade and the consensus seems to be Surrey is on sound legal ground but there should be a debate about whether intellectual property in the matter of the use of materials should be extended to art.

Friday, February 14, 2020

Narthex

Narthex (pronounced nahr-theks)

(1) In church architecture, a portico (enclosed passage) at the west end of a basilica or church, usually at right angles to the nave and located between the main entrance and the nave.

(2) In botany, a taxonomic genus within the family Apiaceae (umbelliferous plants), now included in Ferula, Narthex asafoetida and thus obsolete.

1665-1675: From the Medieval Latin narthex, from the Medieval Greek narthex (enclosed porch, enclosure (the earlier meaning was “box”), from the Ancient Greek νάρθηξ (narthēx) (giant fennel, scourge (and later “casket” (the Modern Greek νάρθηκας (nárthikas)), and, on the basis of the suffix, probably a pre-Greek word.  The connection between the giant fennel plant and boxes is that the fibre from the stems of the plant was used to make boxes.  In Greek, the word was linked also to νάρδος (nárdos) (nard plant, spikenard, nardin, muskroot).  The Modern Greek νάρθηκας (narthekas) long ago relinquished the early senses and now means either the feature in church architecture or the brace of a sprained wrist or sling of a broken arm.  The plant was well known in Greek mythology.  In the Θεογονία (circa 730–700 BC) (Theogonía (the genealogy or birth of the gods)), known in the West as The Theogony, an epic poem of a thousand-odd lines by the (8th-7th century BC) poet Hesod, it was in hollow fennel stalks that Prometheus conveyed fire from Heaven to Earth.  In Armenia the name for a narthex is gavit.  The adjectival form was narthecal and the plural either narthexes or narthices, the English form preferable for most purposes.

Narthexs were part of many early Christian and Byzantine basilicas and churches, located traditionally to the west of the nave and functioned (1) as a lobby area and (2) as the place where penitents were required to remain.  Although the archaeological record suggests there may have been some early churches with annexes or even small separate structures located nearby which fulfilled the latter function, narthexes seem quickly to have been integrated.  That means that structurally and architecturally, a narthex was part of the building but theologically was not, its purpose being to permit those not entitled to admission as part of the congregation (mostly catechumens and penitents) nevertheless to hear the service and (hopefully) be encouraged to pursue communion.

For ceremonies other than services, the narthex was otherwise a functional space, the church’s baptismal font often mounted there and in some traditions (both Eastern & Western) worshipers would sometimes anoint themselves and their children with a daub of holy water before stepping foot in the nave and some branches of the Orthodox Church use the narthex for funeral ceremonies.  There were also architectural variations in the early churches which persisted in larger building and cathedrals, the narthex divided in two, (1) an esonarthex (inner narthex) between the west wall and the body of the church proper, separated from the nave and aisles by a wall, trellis or some other means and (2) an external closed space, the exonarthex (outer narthex), a court in front of the church façade with a perimeter defined by on all sides by colonnades.

In the Western Church, reforms removed the requirement to exclude from services those who were not full members of the congregation which of course meant the narthex was rendered technically redundant.  However, the shape churches had assumed with a narthex included had become part of the tradition of the Church so architects continued to include the space, both as part of the nave structure and something semi-separated.  They attracted a number of names, borrowed mostly from secular buildings including vestibule, porch, foyer, hallway, antechamber, anteroom, entrance, entry, entryway, gateway, hall, lobby, portal & portico, the choice dictated sometimes by local tradition, sometimes by the nature of construction and sometimes, it seems to have been entirely arbitrary.  In the Eastern Orthodox Church, the esonarthex and exonarthex retained distinct liturgical functions, some rituals terminating in the exonarthex while services still exclusively penitential services are usually chanted in the esonarthex.  In dialectal northern English, the casual term for the penitents forced to remain in the narthex was “the narts”.

The NART Ferrari spiders

1966 Ferrari 275 GTS

Although Ferrari produced the 275 GTB (berlinetta (coupé)) (1964-1968) and 275 GTS (spider (roadster)) (1964-1966) in unison with substantially the same mechanical specification, the two had completely different coachwork, sharing not one external panel.  Styled by Pininfarina, the 275 GTS, elegant and well-proportioned, recalled the earlier 250 Cabriolets and buyers appreciated the sophistication of the improved specification but Luigi Chinetti (1901-1994), Ferrari's North American distributer, remembering the sensuous lines of the 250 California Spider (1957-1960), asked the factory for a run of spiders (roadsters) based on the 275 GTB.

1960 Ferrari 250 California Spider

Ferrari commissioned its traditional coachbuilder, Carrozzeria Scaglietti, to produce the series and in 1967, the first tranche of ten of a planned twenty-five was completed and delivered to the United States.  The spiders were based on the newly-released 275 GTB/4 which included a number of refinements to the original series, most notably the twin-cam heads, the factory rating the 3.3 Litre (201 cubic inch) V12 at 300 horsepower, a lift of 20 over the earlier single-cam engines.  Because Chinetti’s competition department was called the North American Racing Team (NART), the ten roadsters have always been referred to as the “NART Spiders” and although the factory never adopted the designation, Chinetti added to the tail of each a small cloisonné badge with the team's logo.  Interestingly, the factory also continued to list the cars as 275 GTB/4s, even though the usual naming convention would have been to designate them as 275 GTS/4s, a hint perhaps from Ferrari that it really wasn’t their idea.

1967 Ferrari 275 GTB/4

The addition of the badge, an unusual addition to anything from Scaglietti workshops, was not unreasonable given the spiders were very much a co-production, Chinetti receiving technical assistance and the precious benefit of official status from the factory but it was made clear that financial responsibility for the project lay exclusively with the US operation which would be required to pay for each prior to delivery.  On that basis things proceeded but, modified from production 275 GTB/4’s with (then typically Italian) labour-intensive coach-building techniques, the spiders were expensive and sales were slow, American buyers more seduced by Ferrari's new and more luxuriously trimmed and cheaper 330 GTS; even then air-conditioning was a persuasive inducement and the more spartan NARTs languished for some months in Chinetti’s showroom waiting for someone with a longing for the ways things used to be done.  As a consequence, it was only that first run of ten which was built but they’ve since become highly prized by collectors, NART #10709 in August 2013 selling at auction for US$27.5 million (including commission) at RM Sotheby's in Monterey, California.

1969 Ferrari 275 GTB/4 NART Spider

Daytona 24 Hours, 1967: First-Ferrari 330 P3/4 (#23; Chris Amon & Lorenzo Bandini), Second-Ferrari 330 P4 (#24; Mike Parkes & Ludovico Scarfiotti and Third-Ferrari 412 P (#26; Pedro Rodriguez & Jean Guichet.

However, despite the modest demand for the NART spiders, Ferrari must have been convinced the concept was viable with full factory backing and when, in 1968, the 275 GTB/4 was replaced with the 365 GTB/4 (1968-1973), a companion spider was listed as an official model, again built by Carrozzeria Scaglietti.  This model came to be known as the Daytona in recognition of Ferrari’s 1-2-3 finish in the 1967 24 Hours of Daytona even though the cars which contested the race were different models, the connection being some photographs from the race which were used in promotional material when the 365 GTB/4 was released.  It was the first new model since the 1-2-3 finish and the name stuck, an attachment about which Ferrari seemed never much enthused although views seem to have softened over the years and "Daytona" appears now even on the corporate website.  The V12 was now 4.4 litres (268 cubic inches) and generating some 340-355 horsepower (depending on market) although the figure on which many fixated was the claimed top speed of 174 mph (280 km/h), the need to out-pace the mark of 171 mph (275 km/h) set by the Lamborghini Miura P400 in 1966 said to be one of the design objectives.  Quite a few verified Ferrari’s claim; few attempted it in the somewhat trickier to handle Miura although contemporary reports confirmed the factory's number.  The Ferrari might actually have gone faster, given enough road.  Luigi Chinetti (1901–1994), who drove the competition version of the Daytona in the 1971 Le Mans 24 hour classic (the last year before the 3.7 mile (6 km) Mulsanne straight was spoiled by the chicanes the FIA imposed) reported than on Mulsanne it never actually stopped accelerating.  Remarkably, the Daytona finished fifth, even winning the mysterious Index of Thermal Efficiency.  Whatever it was, Ferrari must have been content with the thing's terminal velocity but Lamborghini wanted bragging rights and the more powerful Miura P400 S debuted in 1969 with a claim of 180 mph (290 km/h) which Autosport magazine in 1970 almost matched, clocking 288.6 km/h (179.3 mph).  That turned out to be the decade's high-water mark, the succeeding P400 SV more powerful still but a little slower because the aerodynamics were slightly compromised by the need to add a little width to accommodate some needed improvements and the use of fatter tyres which absorbed a surprising amount of energy.  It would be many years before a production car went faster than the P400 S.    

1972 Ferrari 365 GTB/4 (Daytona)

What was however learned from 275 NART experience was that the customers had become sybarites who wanted cars which looked like the austere roadsters of old but fitted with the accruements of modernity, air conditioning, power steering and electric windows.  On that basis the Daytona entered production and in what was by then a much more competitive market, the approach was vindicated, the Daytona close to doubling the sales of its predecessor, including 122 spiders.  Intriguingly, within a few years of the end of Daytona production ending, the realization hit that there wouldn’t again be something like the 365 GTS/4, the days of the big, front-engined V12s thought over and even if one returned, the feeling in the 1970s was that government regulations would be there would be no more roadsters and interest in Daytona spiders began to spike.  With only 122 produced, the math of the supply-demand curve was predictable and prices of spiders soared above the berlinetta, the factory having made more than ten times as many of them.

1971 Ferrari 365 GTS/4 (Daytona)

Thus stimulated was the roofectomy business which had long been part of the coach-building trade but few conversions were potentially as lucrative as a Daytona.  Done properly, the results could be satisfactory but, beyond the roof, there were a number of differences between the two and not all were done properly.  However it’s done, a genuine Scaglietti spider is going to be worth some multiple of a conversion in similar condition, which may now attract little premium over a berlinetta, originality now more of a fetish than it was in the 1970s and 1980s.  In 2013, the New York Times reported Ferrari, unhappy about what they regarded as fakes being traded, were going to try to pressure the high-end auction houses not to host such sales but the industry persists and there are a number of replica 275 NARTs although, not all were based on a twin-cam original, industry sources suggesting a premium above a berlinetta of 20% at most.  Other popular candidates for conversion include the Mercedes-Benz 280 SE 3.5 Coupés (1968-1971; on which an exact conversion is also very challenging), Maserati Ghiblis (1967-1973) and the early Jaguar E-Types, technically a simpler job especially in years gone by when suitable cars were both cheaper and more numerous.

1976 Ferrari 365 GTB/4 NART by Michelotti 

In a footnote to the Daytona’s history, either not discouraged by his experience with the 275 NART or impressed by the prices the ten were commanding, Luigi Chinetti commissioned the construction of five 365 GTB/4 Daytona NART Spiders, the design turned over to Giovanni Michelotti (1921–1980).  In the spirit of 1950s minimalism, Michelotti’s first design, shown at the 1974 Turin Motor Show featured cut-down doors and a removable targa top but the second, built for the 1975 24 Hours of Le Mans, was more a conventional race-car, its lines attuned to aerodynamic enhancement although it never made the event because of a dispute with the notoriously difficult stewards.  Still interested in the concept however, in 1976 Chinetti ordered three more NART Daytonas from Michelotti, configured this time as road-cars with air conditioning and electric windows, the target market the US.  Unlike the 275 NARTs, the three NART Daytonas really were used cars, production of the originals having ceased in 1973.  One of them has been a fixture on the show and auction scene for a while, Michelotti using it as a display piece and it spent two years as an exhibit at the Le Mans Museum before bouncing around the premium auction circuit where it’s exchanged between collectors at increasingly higher prices.  The wedge shape certainly marks the design as a product of the age but so did the detailing: instead of a delicate cloisonné on the tail, NART was printed in big, bold, upper-case letters.

Thursday, February 13, 2020

Thermal

Thermal (pronounced thur-muhl)

(1) Of, relating to, or caused by heat or temperature (also thermic); of, relating to, or of the nature of thermae.

(2) As (both noun and adjective) thermal blanket or thermal underwear (as a noun, always referred to in the plural (thermals) even if describing a single item), items designed to aid in or promote the retention of body heat.

(3) In meteorology, a column of rising air caused by local unequal heating by the sun of the land surface, especially such a current when not producing a cloud; widely used in aviation and of especial importance in gliding, a borrowing of the techniques used by birds. The air usually rises until it is in equilibrium with the surrounding atmosphere.

(4) In stonemasonry, a rough finish created with a blowtorch.

1756: From the French thermal (buffon), from the New Latin thermalis, from the Ancient Greek θέρμη (thérmē) (heat; feverish heat), from the primitive Indo-European gwher (to heat, warm).  The construct was therm + -al (from the Latin adjectival suffix -ālis, or the French, Middle French & Old French -el, -al; used mostly but not exclusively with word of Latin origin).  The sense of "having to do with heat" is first recorded 1837; the noun meaning "rising current of relatively warm air" was first noted in 1933 in the context of aviation.  Geothermal first used in 1875; hydrothermal in 1855, exothermal in 1874; athermanous in 1839, hyperthermia in 1878, isotherm in 1850, endothermic in 1869 (1947 as applied in biology) and thermometer as early as the 1597 although the most familiar (pre-digital) version with mercury encased in glass, was invented by Fahrenheit in 1714.  Thermal is adjective in the singular and a noun in the singular or plural, thermally is the adverb.  The most common derivations are the adjectives hyperthermal and the adverb hyperthermally but in engineering and science there’s also therm, therma, thermacogenesis, thermae, aerothermal, thermometric, thermometrical & thermaesthesia.  Thermal is a noun, verb & adjective; the noun plural is thermals.

Thermal Reactive Nail Polish

Thermal reactive nail polishes change color depending on both body and ambient temperature.  Nail polish is especially suitable for thermal reactivity because the extremities of the body (fingertips, toes, ears & nose) vary in temperature much more than parts closer to the core.  Usefully, they work with even the thickest base and top-coats which affords additional protection for the thermal-reactive chemicals, the color-changing properties affected not at all if multiple coats are applied.

The process is entirely heat-dependent and thus constantly variable.  In this example the reaction produces purple in reaction to cold and aqua to warmth; because the temperature of the nail greatly can vary between base and tip, the ombré effect (colors blending from one hue to another) will fluctuate.  The chemical reaction does rely on the top coat being fully dry and, depending on manufacturer, this can take up to an hour.  The special properties don't last forever but, if correctly sealed, stored in a dark place and not exposed to extremes of heat and cold, the liquid will for months continue to be reactive.

Chemically, the thermal reactivity works because the polish is infused with a leuco (“white” in Ancient Greek) dye, the word a little misleading in this context because leuco dyes have two forms: one clear, the other colored. The reversible transition between the two colors may be caused by heat (thermochromism), light (photochromism) or pH (halochromism) and in other (often industrial) applications, it’s possible irreversibly to change colors, usually from a redox reaction.

For thermal nail polish, the dye comes packaged in tiny spheres called microcapsules, each only 1-10 microns in diameter but containing three chemicals: (1) leuco dye which changes color reversibly, the color depending on the dye which, when combined with a proton or hydrogen ion, becomes colorless.  (2) A weak acid which acts as a catalyst, donating the hydrogen ion.  (3) A solvent which induces a color change at a desired temperature.  When cool, the solvent solidifies, the hydrogen remaining stuck to the acid and thus not interacting with the colored dye.  When hot, the solvent melts, the weak acid dissociates, the hydrogen ion binds to the dye, and the dye is colorless.  The temperature-shift range is about 5ºF (3ºC).

Those not content with the commercially available color combinations easily can brew their own thermal reactive polish.  Leuco dyes are available in many colors and come as a powder, slurry, epoxy, or water-based ink but only the powder is suitable and the transition range should hover 88ºF (31ºC) because nails are cooler than body temperature.  The choice of polish color dictates the result.  A white polish will produce a pastel result, a pale color will switch between the original and the combination of the leuco and the color so a mix of pink polish and a blue leuco dye yields a color shift from pink to purple.

To mix, place 1-2 small ball bearings in empty nail polish bottle and fill with polish to about half-way.  Add leuco dye to achieve desired color (about teaspoon) and, if ambient temperature is high, chill the bottle to see result.  When mixing, cap bottle and gently roll it; do not shake because this will cause cavitation, the formation of air bubbles which impede the blending.  If the polish is too thick, add a few drops of nail polish thinner or clear top-coat but never acetone or other nail polisher remover because these chemicals ruin the mix.  Glitter or holo may be added according to taste.

Lindsay Lohan on skis in fuchsia, Falling for Christmas (Netflix (2022)), her thermal base layer unknown.

When skiing or mountain climbing, thermal underwear is usually the ideal choice for what is called the “thermal base layer”, a combination which consists usually of a top and a pair of leggings.  Outer layers of ski clothing perform better when a thermal base layer is worn because the moisture from the body rapidly is wicked away in a capillary action, permitting the breathable fabrics of the outer garments more efficiently to dissipate the moisture more efficiently.  It’s often thought the only purpose of thermal underwear is to increase body temperature but it’s the symbiosis between the thermal base layer and the outer coverings which regulate body temperature, maintaining comfort in both colder and warmer conditions.  By volume, most thermal underwear is made from Polyester (a type of plastic called polypropylene), often augmented with Lycra and all these garments are produced in a very tight weave which delivers good thermal qualities and what the manufacturers call a high “breathability factor”.

Also used is fine wool which, being a natural fibre, is preferred by many and it does posses the virtues of offering both comfort and efficient thermal qualities.  The choice between the types of construction is less about specific differences in thermal performance than how one’s skin reacts and sometimes this is something which can be judged only after prolonged exposure in a variety of temperatures.  All types are available in both short and long (sleeves & legs) versions and because the material is so thin, the longer cuts intrude not at all upon the fit of gloves and boots and the choice is again one of personal preference although, in extreme conditions, the full-versions should always at least be packed.

Wednesday, February 12, 2020

Tenterhook

Tenterhook (pronounced ten-ter-hook)

(1) One of the hooks or bent nails that hold cloth stretched on a tenter.

(2) As “on tenterhooks”, in a state of uneasy suspense or painful anxiety.

1470–1480: A compound word tenter + hook.  Tenter (wooden framework for stretching cloth) is from the circa 1300 Middle English tenter and is of uncertain origin but thought probably borrowed from Latin via Old French (although the evolution of the ending is wholly obscure).  The source was the Latin tentorium (tent made of stretched skins) from tentus (stretched), a variant past participle of tendere (to stretch), from the primitive Indo-European root ten- (to stretch).  Hook is pre-900, from the Middle English hoke, from the Old English hōc, from the Proto-Germanic hōkaz (which influenced also the West Frisian & Dutch hoek (hook, angle, corner), the Low German Hook, variant of hakô (hook), the West Frisian heak and the Dutch haak (hook)).  It’s probably ultimately from the primitive Indo-European kog-, keg- & keng- (peg, hook, claw).

Tenterhooks.

The plural form tenterhooks (one of the hooks that holds cloth on a tenter) was noted first in the late fifteenth century but the figurative phrase “on tenterhooks” is from 1748 and its more evocative imagery meant it soon supplanted “to be on tenters” which had been in use since the 1530s.  The phrase “on tenterhooks” came to mean “being in a state of tension, uneasiness, anxiety, or suspense” figuratively stretched like the cloth on the tenter.  Improvements in the design of machines means tenterhooks are no longer widely used in cloth manufacturing, the word tenterhook is now used almost exclusively used in the metaphorical sense.

Those on tenterhooks waiting for new Lindsay Lohan content were glad to learn of the two-film deal with Netflix, Falling for Christmas released in November 2022 while Irish Wish is scheduled for debut in 2023.

The phrase “on tenterhooks” is one of the most misspoken in English, often pronounced as “tenderhooks”.  Only “Parthian shot” suffers more, rendered frequently as “parting shot”, a more understandable mistake given the context.