Jack Forster
[Elite User]
4381
Something a little different: The 'Icarus' Sundial. . .
A Modern Astrolabe: the Icarus Sundial by Helios
Perhaps the truest ancestor of modern mechanical timepieces currently known to modern archaeology is the device known as the Antikythera Mechanism (O mēchanismós tōn Antikythērōn) which was discovered in the spring of 1900 by one Elias Stadiatos, a Dodecanese sponge diver. Like all mechanical timepieces from antiquity to the modern era, the Antikythera device is essentially an analogue computer; it is one of the earliest devices known which uses toothed gears, and is apparently an astronomical computer. It appears to have been used to calculate the positions of the sun and moon, as well as possibly the five ancient planets known to the Greeks and other ancient astronomers, and it is even possible that it may have been part of a larger mechanism with a water escapement- a clepsydra, or water clock. The likelier procedure however was that the mechanism needed to have the date in question set by hand.
Main fragment of the Antikythera Mechanism
As such, the Antikythera Mechanism is the hubristic ancestor of all clocks and watches; hubristic because rather than observe the universe, it attempts to model or encapsulate some aspect of it; to express the hidden, the arcane, and the occult in the relationship of gears and wheels. With the addition of an escapement- whether dripping water, as refined by the great inventor Ctesibius of Alexandria (who was known also for his automata- a sort of Jaquet Droz of the ancient world) or a pendulum, or hairspring regulated balance wheel- you have an expression which though ostensibly reverential of the Divine Order is in fact a symptom of the desire to master physical laws rather than observe them- technology, in a word, as much as philosophy.
A 16th century astrolabe
At the opposed pole in terms of intention, are those devices or contrivances that simply bring order to our perceptions. The sundial is in this category. In its earliest form, the sundial was probably nothing more than the observation of primitive man that the shadow of a stationary upright object moves in a predictable arc across the ground as the sun progresses across the sky. The identity of the first individual to whom it occurred to mark the divisions of time as the day progressed, so they could be reckoned and the day’s activities ordered, is of course lost to antiquity. Like most good ideas it certainly occurred more than once. It seems a reasonable assumption that an indispensable prerequisite is settled civilization and in fact evidence of recognizable sundials, first in the form of obelisks and later in more familiar guises, appear relatively late in the historic record; more or less simultaneously in various places in the ancient world, around 700-500 BCE.
A vertical sundial on the wall of a building in Warsaw
Sundials had, and still have, many disadvantages, not the least of which is that they don’t work should the weather be less than clement, or should it be nighttime; their great advantage however is that since they tell the time from the unvarying progress of the sun across the sky they will never fail of accuracy. Any modern horological enthusiast who has endured a frustrating wait for the repair of a mechanical timepiece as it languishes in the queue at an authorized brand repair center, will appreciate that the paucity of moving parts in a sundial is also not without its attractions. So significant were the advantages of a sundial over the fussy, variable, and expensive horologia of centuries past, in fact, that it was not until industrialization and the need for time standards for transport and communication, that the sundial finally became what it is today- no more than a decoration, nothing more than a lawn ornament.
The sad fate of the modern sundial?
Human ingenuity however is not content to merely leave well enough alone, and to consign the sundial to the dust heap of history would be premature. Indeed for horological enthusiasts, the resurrection of and reverence for thoroughly outmoded technology is par for the course, and to the historically minded student of the art, the arcana of planes of the ecliptic and analemmae must necessarily exert an irresistible attraction. The sundial, in other words, was long overdue for a facelift and the task fell to an ingenious inventor named Dr. Carlo Heller. An engineer who from childhood was obsessed with and fascinated by astronomical phenomena, Dr. Heller has devoted his fertile imagination to the development of technologically unique and aesthetically compelling sundials of unsurpassed accuracy, elegance and ingenuity, which would have made any Babylonian court astrologer or Greek stargazer weak in the knees. While several of Dr. Heller’s inventions are intended to function, as most sundials do, as stationary devices, he has recently developed a sundial which is small enough to fold into a satisfyingly flat and compact package that can be worn on the belt, and which manages to combine an almost incredible range of functions.
This sundial is the Icarus. It is however doing it poor justice to call it a sundial; perhaps its closest relatives are the complex astrolabes produced during the Middle Ages. The astrolabe was essentially a hand-held observational device, with which one took a visual fix on a heavenly body and with which one could calculate the time, predict the rising and setting of the sun and the moon, as well as solve other astronomical problems. The Icarus sundial however not only encompasses many of the functions of the astrolabe, it also incorporates features of especial interest to the modern sundial enthusiast.
The structure of the device is deceptively simple. The Icarus is a flat sheet of oval metal with a rotating disk in the center that carries on each face a projection of either the northern or southern hemisphere of the Earth. Running through the center of the Earth disk, directly through the location of the poles on the projected map, is a very thin steel wire, with a small oval nodule of metal suspended on it. In use, the Icarus is held suspended from a ring that runs through an adjustable nut that can be moved along an arc above the Earth disk in order to set the latitude at which one is making one’s observations; with the Earth disk in the correct orientation and the Icarus sundial held in the right orientation to the sun in the sky, the correct time can easily be read to a very high degree of accuracy.
One is not limited, however, to simply reading the time. Time, of course, can mean many things and the simplest “time” one can tell from a sundial is simply the time in one’s current exact physical location, based on the position of the sun in the sky. This is the so-called apparent solar time. However, the rate of movement of the sun across the sky varies as the year passes- that is, if one for instance calculates the time between each moment on successive days when the sun reaches its highest point, one will find that the time interval does not always come to exactly 24 hours; it may be as much as a quarter of an hour (approximately) fast or slow depending on the time of year. A sundial therefore will not always tell the same time as a clock, whose rate does not vary. The difference between time told by a clock at a particular spot on the Earth’s surface, and the time told by a sundial, is known as the Equation of Time- an indication that one sometimes sees built into early accurate long case pendulum clocks, as during the time such clocks were first being made sundials were still in common use, and the difference between apparent and mean solar time still a valuable piece of information. The reason for this variation has to do with two factors: the elliptical shape of the Earth’s orbit, which causes the speed of the Earth around the sun to vary, and the inclination of the celestial equator to the plane of the ecliptic along which the sun moves.
In addition to allowing one to calculate the Equation of Time instantly for one’s location, and at the same time read mean solar time, the Icarus also allows one to read the time for one’s time zone, or standard time, which may vary somewhat from local apparent solar time as well. As if this were not enough the Icarus can be used to quickly determine the standard time for any location in the world, immediately determine in which sign of the Zodiac the sun is located- that is to say, it can show the position of the Sun along the celestial equator- and it can further be used as a solar compass. Finally, it can even serve as a navigational instrument- to calculate the latitude one merely need take successive readings of the altitude of the sun around noon; the longitude can be calculated as well although in order to do so one must concede to the mechanical timekeeper and pay homage to the genius of John Harrison and other early marine chronometer inventors- for although the Icarus can be used to calculate the longitude, one must know the time at Greenwich, at the Prime Meridian, in order to do so.
Despite this last minor lapse in utter self sufficiency, the Icarus is a masterpiece of brilliance in economy of design. With a minimum of parts, and an ingeniously simple design, it makes available to the owner a portable means of ascertaining apparent solar, mean solar, and standard time, as well as functioning as a worldtimer, equation of time displaying, astrological instrument also capable of giving navigational information! For less than the price of a buckle from a top tier horological manufacture one may have an instrument that is a rightful heir to and a direct connection with two and a half thousand years of astronomical and horological observation. To use the Icarus is to have an uncanny sense, not often offered, of the connection between the terrestrial and the celestial, and to a real horological purist it is a beautiful and truly philosophical accomplishment.
Jack Forster
All images from the Helios website
click here to visit, and see some other remarkable sundials
Icarus sundial kindly provided by Mr. Timm Delfs of:
Felix Solis Tempus
Rebgasse 41
CH-4058
Basel
Something a little different: The 'Icarus' Sundial. . .
