Kitobni o'qish: «A History of Inventions, Discoveries, and Origins, Volume II (of 2)», sahifa 21

VANES. WEATHERCOCKS

If the poet Seneca was well informed, mankind, in the infancy of navigation, had no particular names for distinguishing the principal winds⁶⁶¹. This is not at all incredible; because with their rafts and floats, which were the first vessels, they for a long time ventured out to sea only so far that they could easily return to the shore; and therefore while navigation continued in this state, they had little reason to trouble themselves about the direction of the winds. It is more certain that those nations respecting whom we have the oldest information, distinguished by names the four principal winds only. This is generally proved by a passage in Homer, where he intends to mention all the winds, and names only four⁶⁶²; but this proof is of little weight; for what poet at present would, with the like view, think of boxing the compass, or of introducing into a poem the names of all the thirty-two points? Would he not rather be satisfied with the names of the four chief winds alone? If more names, therefore, were usual in Homer’s time, he would not consider it necessary to name them. In another passage he names only two winds⁶⁶³; and from these some have endeavoured to prove that no more were then known; but this assertion indeed is completely refuted by the passage first quoted. It can, however, be easily proved, that for a long time names were given to the four principal winds only.

It is easily seen what at first gave rise to this distinction. The sun at noon stands always over one point of the horizon, which appears to the observer as a circle, having the place where he himself is at its centre. This point is called the meridian or south, and the one opposite to it the north. If the observer turns his face towards the north, he will have on his right-hand the east, and on his left the west. The space between these principal winds contains ninety degrees, or a right angle. The number, however, must soon have been raised to eight, and this division was usual in the time of Aristotle⁶⁶⁴. Afterwards twelve points in the heavens were adopted, also as many winds; and in the time of Vitruvius twenty-four were distinguished and named, though this division was very little used. To determine the names, however, employed in the last two divisions is attended with some difficulties; and it almost appears as if writers did not always apply to them the same meaning.

The Greeks considered Æolus as the first person who made navigators acquainted with the winds. He is said to have ruled over the Volcanic islands, afterwards named the Æolian; and if this be true, he would certainly have a good opportunity of observing the weather, and marking the winds by the smoke continually rising up there from burning volcanoes. This celebrated personage, who received Ulysses on his return from the Trojan war, by the knowledge thus obtained may have assisted navigators, who afterwards made known the services which he rendered to them.

The antiquity of the division into thirty-two points, used at present, I am not able to determine. Riccioli thinks that they have been employed since the time of Charles the Great, but I do not know whether this can be proved. That assertion perhaps is founded only on the opinion, that this emperor gave German names to the winds and the quarters of the world. This indeed is stated by his historian Eginhart, who mentions the names, which I shall here insert, together with the Latin names added by Eginhart, and those usual at present⁶⁶⁵.

It has however been long since remarked, that these names are much older than Charles the Great⁶⁶⁶; and it is highly probable that they were only more accurately defined, or publicly confirmed by this prince, or that in his time they came into general use. How often have early inventions been ascribed to sovereigns, though they were only made in their reign! Even whole nations have been said to be descended from those princes under whom they first became known to foreigners; as, for example, the Poles from Lech, and the Bohemians from Zech.

Charles, however, did not give names to thirty-two, but to twelve winds. Nor was he the first who added to the four cardinal points eight others, for the same thing is asserted of many. But it deserves to be remarked, that in Charles’s names one can discover traces of that ingenious mode of denoting all the winds with four words; that is to say, by different combinations of East, West, South, and North. It is certain that the names of the different points and winds used by all the European nations, the Italians only excepted, are of German origin, as well as the greater part of the terms of art employed in navigation and naval architecture.

It appears to me not improbable that the division used at present was introduced soon after the invention of the magnetic needle; at least Honorius, surnamed Augustodunensis⁶⁶⁷, who must have flourished before the year 1125, speaks only of twelve winds; as do also Gervasius in 1211, and Vincent de Beauvois in the middle of the thirteenth century, who gives from Isidorus, who lived about the year 636, the twelve Latin names used by Eginhart⁶⁶⁸.

It can scarcely be doubted that means for indicating the winds were invented at a very early period. I here allude to vanes, flags, and every other apparatus by which the direction of the wind can be conveniently and accurately discovered, and similar to those erected at present on many private houses, on most of our church steeples, and on board ships. I must however confess that I have hitherto scarcely observed any trace of them among the Greeks and the Romans. I can find no account of them in works where all the parts of edifices are named; where ships and everything belonging to them are expressly described; nothing in Pollux, and nothing in any of the poets. I am unacquainted also with any old Greek or Latin word that can be applied to an apparatus for pointing out the wind. In the edition of Kirsch’s German and Latin Dictionary, printed in 1754, we find Wetterhahn (a weathercock) petalum, triton; but the latter term is borrowed from the tower of Andronicus, of which I shall have occasion to speak hereafter; and neither this word nor petulum, or petulæ, arum, which Kirsch gives also, occurs in this sense in any ancient author; and the case is the same with pinnacella, ventilogium, aurologium, and other names which are to be found in some dictionaries.

I am acquainted with no older information in regard to an apparatus for observing the winds, than what is given by Vitruvius respecting the tower built at Athens by Andronicus Cyrrhestes, that is, of Cyrrhus, a town in Syria. This tower, which was built of marble, in an octagonal form, had on each side a representation of that wind opposite to which it was placed. Its summit terminated in a small spire, on which was a copper triton, made to turn in such a manner as to present its front to the wind, and to point with a rod held in its right-hand to the image of the wind blowing at the time⁶⁶⁹. This tower is still standing; and a description and figure of it may be seen in the travels of Spon and Wheeler, and in those also of Pocock⁶⁷⁰. The figures representing the winds, which are larger than the life, are executed in basso-relievo, and correspond to the seasons at which they generally blow. At the top of each side, under the architrave, the name of the wind is inscribed in Greek characters. Boreas, the North wind, holds in his hand a mussel-shell, which seems to denote his peculiar power over the sea. The Zephyr has its bosom full of flowers, because it prevails in March, at the time when the flowers chiefly blow in Greece; and similar attributes are assigned to the rest.

Varro had an apparatus of the same kind at his farm⁶⁷¹. Within the building was a circle, in which the eight winds were represented, and an index, like that of a clock, pointed to that wind which was blowing at the time. Nothing therefore was necessary but to look at the ceiling to know from what quarter the wind came. I have seen an apparatus of the same kind on some exchange, either at Lubec or Rotterdam. Varro calls the tower of Andronicus horologium, a word which Salmasius wishes to change into aurologium. But it contained also a sun-dial, as we are assured by Pocock, who observed the necessary hour-lines; and therefore it is not improbable, that the people, who through the want of clocks would oftener look to the dial than to the weathercock, gave to the tower a name alluding to the former rather than to the latter.

Du Cange says, that a triton, by way of weathercock, was placed on the temple of Androgeus at Rome; but I am unacquainted with the source from which he derived this information, and of that temple I have not been able to obtain any account⁶⁷². Whether the tritons placed on the temple of Saturn at Rome were indicators of the wind, or whether they had a learned signification, as Macrobius asserts, I will not venture to determine⁶⁷³. It is probable that the pillar, some remains of which were found at Gaeta (Cajeta), in the kingdom of Naples, and on which the names of the winds were cut out in Greek and Latin, served as a wind indicator also.

But it is more than probable that an apparatus for pointing out the wind, similar to that at Athens, was erected also at Constantinople. At least I consider as such what was called by some anemodulium, and by others anemoderium; the information respecting which has not, as I conceive, been hitherto understood, not even by Banduri. In my opinion it was not a building or tower, but a column furnished with a vane, somewhat similar to what is still seen in many places on the sea coast, where a high pole is erected with a flag. This pillar, if I may be allowed the expression, consisted entirely of copper; it was square, and in height not inferior to the loftiest columns in the city. Its summit formed a pyramid, and, as I conjecture, an octagonal one, upon which stood a female figure that turned round with every wind, and consequently was a vane, only not a triton, as at Athens. Below it, on each side of the pyramid, were seen a great many figures, which I will venture to assert were attributes or images of the winds, to which the female figure pointed. Nicetas says, that there were observed among them birds, agricultural implements, the sea with shipping, fishing-boats, and naked cupids sporting with apples, which in my opinion denoted the different seasons in which each wind was accustomed to blow⁶⁷⁴.

It is not improbable that the whole pillar was constructed of different pieces of copper, cast singly and then joined together; and it appears that neither Nicetas, nor Cedrenus, nor the Latins, who in the thirteenth century pulled down and melted the numerous objects of art, plundered from various cities by the emperor Constantine to ornament his capital, were acquainted with the purpose for which this pillar was originally destined, or the meaning of the emblematical figures represented upon it. Nay, there is even reason to think that the Greeks themselves, at this time, were so ignorant as to believe such objects to be the productions of magic. According to Cedrenus, this costly wind indicator was erected by Theodosius the Great, and according to others by Leo Isauricus. Were the first assertion true, it would belong to the fourth century, and in the second case to the eighth; but I cannot help suspecting that it was constructed before the time of Theodosius. The female figure which indicated the wind, was, according to Nicetas, called anemodoulon, but according to Cedrenus anemoderion. The former denotes a person who belongs to the wind; the latter one who contends with the wind; and both these appellations are well suited to a vane or wind indicator. If my explanation be correct, this work of art at Constantinople had nothing in common with the statue of Jupiter constructed by Lysippus at Tarentum⁶⁷⁵. The latter was forty cubits in height; and what excited great astonishment was, that though it would shake when pushed with the hand, it withstood the force of the most violent storms. I should rather compare the statue of Lysippus to those moveable masses of rock which are mentioned by various authors, both ancient and modern.

It is not improbable that there may have been wind indicators of this kind in other places, and that more passages alluding to them, not hitherto remarked, may be found in different authors. Professor Michaelis, who was desirous to assist me in my researches, pointed out to me an account, undoubtedly written before the year 1151⁶⁷⁶, in which it is stated that there was at Hems, in Syria, formerly called Emessa, a high tower, on the summit of which was a copper statue of a horseman that turned with every wind. It is worthy of remark, that under the vane there were figures, among which was that of a scorpion; in all probability the emblem of some season.

In Europe, the custom of placing vanes on the summits of the church-steeples is very old; and as these vanes were made in the figure of a cock, they have thence been denominated weathercocks. In the Latin, therefore, of the middle ages, we meet with the words gallus and ventilogium. The latter is used by Radulphus, who wrote about the year 1270⁶⁷⁷. Mention of weathercocks occurs in the ninth⁶⁷⁸, eleventh, twelfth and thirteenth⁶⁷⁹ centuries. There is no doubt that the cock was intended as an emblem of clerical vigilance. In the ages of ignorance the clergy frequently styled themselves the cocks of the Almighty, whose duty it was, like the cock which roused Peter, to call the people to repentance, or at any rate to church⁶⁸⁰. The English, therefore, are mistaken when they suppose that the figure of a cock was first made choice of for vanes in the fourteenth century, under the reign of Edward III., in order to ridicule the French, with whom they were then at war; and that the custom of cock-throwing, that is to say, of throwing sticks at a cock exposed with his wings tied, as then practised, took its rise at the same time.

In France, in the twelfth century, none but noblemen were allowed to have vanes on their houses; nay, at one time this was the privilege of those who, at the storming of a town, first planted their standards on the ramparts. These vanes were painted with the knights’ arms, or the arms were cut out in them, and in that case they were called panonceaux⁶⁸¹.

Flags or vanes on ships occur very early, but they are always mentioned on account of their use in making signals. They were of various forms and colours; were sometimes drawn up, and sometimes taken down; placed sometimes on the right and sometimes on the left side of the ship, and were changed in various other ways, directions for which may be seen in the Tactics of the emperor Leo. They were named vexilla, flammulæ, also flammula and banda, and the last two appellations occur in the works of the younger Greek writers⁶⁸².

But though the oldest writers on the art of naval warfare, such as Vegetius, recommend a knowledge of the winds, I have not yet met with any certain account of apparatus for determining the direction of them on board a ship. Before the discovery of the magnetic needle, such accuracy as is necessary at present would have been superfluous; yet naval commanders must long before have had some means of distinguishing at least the twelve winds then defined, though no traces of them are to be found in the works which have been accidentally preserved to us.

Scheffer⁶⁸³, who, as is well-known, collected from the works of the ancients all the terms of art applicable to navigation, thinks that the band, tænia, affixed to a pole at the stern of the ship⁶⁸⁴, did not serve so much for an ornament as to indicate the course of the wind. He is, however, able to produce no other authority for this opinion than a passage in one of Cicero’s letters, which has been changed and amended, till it at length seems to say that Cicero had resolved to embark, because the vanes had announced a favourable wind⁶⁸⁵.

I must acknowledge that at present I can produce no older information in regard to vanes used on board ship, to indicate the course of the wind, than of the eleventh century, taken from the life of Emma, the consort of Canute the Great, king of Denmark, Norway and England, the author of which was an eye-witness of what he relates. Describing the magnificent Norman fleet sent to England in the year 1013, he says that birds, which turned round with the wind, were placed on the top of the masts⁶⁸⁶.

At that time, therefore, instead of the flags used at present, a vane, shaped like a bird, was placed at the summit of the mast; perhaps also the figure of a cock, as the emblem of vigilance, but in this case not of clerical vigilance. In the cathedral of Bayeux, in France, is a piece of tapestry, representing the actions of William the Conqueror, executed with the needle, either by his consort or under her direction, in which vanes are seen at the top of the masts in many of the ships⁶⁸⁷.

[Anemoscopes, or instruments for showing the direction of the wind, are now in constant use in meteorological establishments; the indications are made upon dials, and the apparatus does not differ in principle from that described by Beckmann.

Anemometers, or instruments for measuring the power or force of the wind, have also been contrived of various kinds. The first was invented by Wolf. In this the wind acted upon four sails somewhat resembling those of a windmill, the motion being communicated by cog-wheels to a lever loaded with a weight. When the wind acted upon the sails, the bar rose, this motion continuing until the increased leverage of the weight counterpoised the moving power of the wind. Others on a different principle have been made by Lind, Regnier, Martin, and a very beautiful instrument for this purpose, constructed by Mr. Dent, may be seen at Lloyd’s room in the Royal Exchange.]

GILDING

The astonishing extensibility of gold, a property in which it far surpasses all other metals, induced mankind, at an early period, to attempt beating it into thin plates, as the value of it led them to the art of covering or gilding things of every kind with leaves of it. It is proved by Herodotus, that the Egyptians were accustomed to gild wood and metals⁶⁸⁸; and gilding is frequently mentioned in the books of the Old Testament⁶⁸⁹. The gold plates, however, used for this purpose, as may be readily conceived, were not so thin as those made at present; and for this reason, the gilding on statues, which have lain many centuries in the earth, appears to be still entire. Winkelmann says⁶⁹⁰, that among the ruins of two apartments in the imperial palace, on the palatine hill, in the Villa Farnese, the gold ornaments were found to be as fresh as if they had been newly applied, though these apartments, in consequence of being buried under the earth, were exceedingly damp. The circular bands of sky-blue, with small figures in gold, could not be seen without admiration. The gilding also is still preserved in the ruins of Persepolis.

But, in the time of Pliny, the art of gold-beating was carried so far at Rome, that an ounce of gold could be beat into seven hundred and fifty leaves and more, each four square inches in size⁶⁹¹. I shall not compare this result with what the art can do at present, because the account of Pliny is not the most accurate, and because the conversion of the old measures into the modern standard is always attended with uncertainty. Buonarotti, however, who made some researches on this subject⁶⁹², is of opinion that the gold used at Rome for fire-gilding in his time, that is, at the end of the seventeenth century, was beat six times as thin; and that the gold employed for gilding wood and other things, without the application of fire, was twenty-two times as thin as the gold leaf made at Rome in the time of Pliny. But this Italian author, as appears to me, has, through too great precipitation, translated the words “septingenæ et quinquagenæ bracteæ” fifty and seventy. Gold, however, at that time, was beat so thin at Rome, that Lucretius compares it to a spider’s web, and Martial to a vapour⁶⁹³.

I have, however, not yet met with any information in regard to the method in which the ancient artists beat the gold, or the instruments and apparatus they employed for that purpose. But the German monk Theophilus, whose real name seems to have been Rüger, and who, as Lessing thinks, lived in the ninth, but, according to Morelli, in the twelfth century, describes the process nearly as it is at present⁶⁹⁴. The gold, at that time, was beat between parchment, in the same manner as is still practised; and the artists knew how to prevent the gold from adhering to the parchment, by covering it over with burnt ochre reduced to a very fine powder, and then rubbing it smooth with a tooth. With the like view, our gold-beaters rub over with a fine bolus the thin paper used for making the books into which they put their gold leaf, in order to preserve it. But the flatting-mills, between the steel rollers of which cast and hammered ingots of gold are at present reduced to thin leaves, seem not to have been then known, at least this monk makes no mention of them. Lessing, to whom we are indebted for this curious fragment of Theophilus, is of opinion that each artist at that time was obliged to beat the gold leaf which he used, because gold-beating was not then a distinct branch of business. This I will not controvert; but it is no proof of it, that the monk taught the art to his brethren; for in convents the clergy endeavoured to make everything they used, in order that they might purchase as little as possible.

During the progress of the art, it being found that parchment was too thick and hard for the above purpose, workmen endeavoured to procure some finer substance, and at length discovered that the skin of an unborn calf was the most convenient. By means of this improvement, gold leaf was made much thinner than it had ever been before possible; but the art was brought to still greater perfection by employing that fine pellicle which is detached from the gut of an ox or a cow. Lancellotti, who wrote in the first half of the seventeenth century⁶⁹⁵, says that this invention was made by the German gold-beaters, when, in consequence of the war, they were not able to obtain from Flanders the skins of unborn calves.

I have often heard that the preparation of this pellicle, which the French call baudruche and the Dutch liezen, and which is so thin that two of them must be pasted together, is a secret, and that the best is obtained from England. But in the year 1785, when I paid a visit to a very ingenious gold-beater at Hamburg, he assured me that he prepared this substance himself, and that the case was the same with most of the gold-beaters in Germany. Even in England, in the year 1763, this art was known only to two or three persons, who practised it as a business, but kept it so secret that Lewis was not able to obtain a proper account of it⁶⁹⁶. In Ireland also this skin is prepared and sent to England⁶⁹⁷. When the French, in the beginning of the revolutionary war, hoped to out-manœuvre the Germans by the use of aerostatic machines, it became of some importance to them to obtain a supply of these skins. On this account, the Commission des armes et poudres drew up instructions for preparing them, which they caused to be printed and distributed to all the butchers. At Strasburg they were printed in French, and at the same time in German, but in many parts faulty and unintelligible.

About the year 1621, Mersenne excited general astonishment, when he showed that the Parisian gold-beaters could beat an ounce of gold into 1600 leaves, which together covered a surface of 105 square feet. But in 1711, when the pellicles, discovered by the Germans, came to be used in Paris, Reaumur found that an ounce of gold, in the form of a cube, five and a quarter lines at most in length, breadth, and thickness, and which covered only a surface of about twenty-seven square lines, could be so extended by the gold-beaters as to cover a surface of more than one hundred and forty-six and a half square feet. This extension, therefore, is nearly one-half more than was possible about a century before.

When these skins are worn out by the hammer of the gold-beater, they are employed, under the name of English skin, for plasters, or properly to unite small wounds. By the English they are called gold-beaters’ skin⁶⁹⁸; but, since silk covered with isinglass and Peruvian balsam, which in Germany is named English plaster, for the Germans at present call every thing English, has become the mode, this skin is much less used⁶⁹⁹. I mention this that I might have an opportunity of remarking, that in the middle of the twelfth century, in the Levant at least, a very thin pellicle was in like manner used for wounds. For when the emperor, John Comnenus, accidentally wounded himself in the hand with a poisoned arrow while hunting, a piece of skin, which, from the name and description may be considered the same as that used at present by the gold-beaters, was applied to the wound. The emperor, however, died in consequence of this wound, after it had become inflamed under the pellicle, which, in large wounds, and when the skin is suffered to remain too long, is commonly the case, though the poison alone would have been a sufficient cause of death. Reaumur and others are astonished that artists should have sought for and found a part of their apparatus in the bowels of an ox; but I am of opinion that this pellicle, which is sometimes separated in washing and cleaning the bowels, was first observed by the butchers, and made known by them as a plaster; and that it came into request among the German gold-beaters, as the finest of all the pellicles then known, in the beginning of the seventeenth century.

The art of gilding, and particularly unmetallic bodies, was much facilitated by the invention of oil-painting; but it must be acknowledged that the process employed by the ancients in cold-gilding was nearly the same as that used at present. Pliny says⁷⁰⁰ that gold leaves were applied to marble with a varnish, and to wood with a certain kind of cement, which he calls leucophoron. Without entering into any research respecting the minerals employed for this cement, one may readily conceive that it must have been a ferruginous ochre, or kind of bole, which is still used as a ground (poliment, assiette)⁷⁰¹. But gilding of this kind must have suffered from dampness, though many specimens of it are still preserved. Some of the ancient artists, perhaps, may have employed resinous substances, on which water can produce very little effect.

That gold-leaf was affixed to metals by means of quicksilver, with the assistance of heat, in the time of Pliny, we are told by himself in more places than one. The metal to be gilded was prepared by salts of every kind, and rubbed with pumice-stone in order to clean it thoroughly, and to render the surface a little rough⁷⁰². This process is similar to that used at present for gilding with amalgam, by means of heat, especially as amalgamation was known to the ancients. But, to speak the truth, Pliny says nothing of heating the metal after the gold is applied, or of evaporating the quicksilver, but of drying the cleaned metal before the gold is laid on. Had he not mentioned quicksilver, his gilding might have been considered as that with gold-leaf by means of heat, dorure en feuille à feu, in which the gold is laid upon the metal after it has been cleaned and heated, and strongly rubbed with blood-stone, or polished steel. Felibien was undoubtedly right when he regretted⁷⁰³ that the process of the ancients, the excellence of which is proved by remains of antiquity, has been lost.

False gilding, that is, where thin leaves of a white metal, such as tin or silver, are applied to the article to be gilded, and then rubbed over with a yellow transparent colour, through which the metallic splendour appears, is much older than I believed it to be in the year 1780. The process for this purpose is given by the monk Theophilus, whose fragments were first printed in 1781⁷⁰⁴. According to his directions, tin beat into thin leaves was to be rendered of a golden yellow colour by a vinous tincture of saffron, so that other pigments could be applied over it. The varnish or solution of resin in spirit of wine or oil, used for this purpose at present, appears not then to have been known. But in the sixteenth century this art was very common; and instructions respecting it were given by Garzoni⁷⁰⁵, Cardan⁷⁰⁶, Caneparius⁷⁰⁷ and others in their writings. About the same period a pewterer at Nuremberg, named Melchior Koch, was acquainted with the art of communicating a golden colour, in the like manner, to tin goblets and dishes. He died in 1567; and with him, as Doppelmayer says, the art was lost. A method of applying a white metal to paper, and then drawing over it a gold varnish, has been known in China since the earliest periods⁷⁰⁸. At present this method of gilding is practised more in Sicily than in any other country. It appears also to have been used, at an early period, for gilding leather and leather tapestry; and this perhaps was first attempted at Messina, as we are told by John Matthæus⁷⁰⁹, who, however, in another place ascribes the invention to a saint of Lucca, named Cita. But gilt leather was made as early as the time of Lucian, who conjectures that Alexander the impostor had a piece of it bound round his thigh⁷¹⁰. The dress of the priests, on the festival of Bacchus, was perhaps of the same kind⁷¹¹.