A History of Inventions, Discoveries, and Origins, Volume II (of 2)

Who first conceived the idea of applying to the fire-engine an air-chamber, in which the included air, by compressing the water, forces it out in a continued stream, is not known. According to a conjecture of Perrault, Vitruvius seems to speak of a similar construction; but Perrault himself acknowledges that the obscure passage in question606 might be explained in another manner. The air-chamber in its action has a similarity to Hero’s fountain, in which the air compressed by the water obliges the latter to ascend607.

I can find no older fire-engine constructed with an air-chamber than that of which Perrault has given a figure and description. He says it was kept in the king’s library at Paris, and during fires could project water to a great height; that it had only one cylinder, and yet threw out the water in one continued jet. He mentions neither its age nor the inventor; and I can only add that his book was printed in 1684. The principle of this machine, however, seems to have been mentioned before by Mariotte, who on this account is by some considered as the inventor; but he does not appear to have had any idea of a fire-engine, at least he does not mention it.

It is certain that the air-chamber, at least in Germany, came into common use after it was applied by Leupold to fire-engines, a great number of which he manufactured and sold. He gave an account of it in a small work, consisting of four sheets quarto, which was published in 1720, but at first he kept the construction a secret. The engines which he sold consisted of a strong copper box closely shut and well-soldered. They weighed no more than sixteen pounds, occupied little room, had only one cylinder; and a man with one of them could force up the water without interruption to the height of from twenty to thirty feet. About 1725 Du Fay saw one of Leupold’s engines at Strasburg, and discovered by conjecture the construction of it, which he made known in the Transactions of the Academy of Sciences at Paris for that year. It is very singular that on this occasion Du Fay says nothing of Mariotte, or of the engine in the king’s library. Leupold, however, had some time before, that is in 1724, given a description and figure in his Theatrum Machinarum Hydraulicarum608, with which undoubtedly Du Fay was not acquainted.

Another improvement, no less useful, is the leather hose added to the engine, which can be lengthened or shortened as necessary, and to which the fire-pipe is applied, so that the person who directs the jet of water can approach the fire with less danger. This invention, it is well known, belongs to two Dutchmen, both named Jan van der Heide609, who were inspectors of the apparatus for extinguishing fires at Amsterdam. The first public experiments made with it took place in 1672; and were attended with so much success, that at a fire next year, the old engines were used for the last time, and the new ones introduced in their stead. In 1677, the inventor obtained an exclusive privilege to make these engines during the period of twenty-five years. In 1682, engines on this construction were distributed in sufficient number throughout the whole city, and the old ones were entirely laid aside. In 1695 there were in Amsterdam sixty of these engines, the nearest six of which were to be employed at every fire. In the course of a few years they were common throughout all the towns in the Netherlands.

All these circumstances have been related by the inventor in a particular work; which, on account of the excellent engravings it contains, is exceedingly valuable610. Of these, the first seven represent dangerous conflagrations at which the old engines were used, but produced very little effect. One of them is the fire which took place in the stadthouse of Amsterdam in the year 1652. The twelve following plates represent fires which were extinguished by means of the new engines, and exhibit, at the same time, the various ways in which the engines may be employed with advantage. According to an annexed calculation, the city of Amsterdam lost by ten fires, when the old apparatus was in use, 1,024,130 florins; but in the following five years, after the introduction of the new engines, the loss occasioned by forty fires amounted only to 18,355 florins; so that the yearly saving was ninety-eight per cent. Of the internal construction of these engines no description or plates have been given; nor do I remember to have read a passage in any author from which it can be concluded that they were furnished with an air-chamber, though in the patents they were always called spouting-engines, which threw up one continued jet of water. The account given even of the nature of the pipe or hose is short and defective, probably with a view to render it more difficult to be imitated. It is only said that it was made of leather in a particular manner; and that, besides being thick, it was capable of resisting the force of the water.

The conveyer or bringer was invented also about the same time by these two Dutchmen. This name is given at present to a box which has on the one side a sucking-pump, and on the other a forcing-pump. The former serves to raise the water from a stream, well, or other reservoir, by means of a stiff leathern pipe, having at the extremity a metal strainer pierced with holes to prevent the admission of dirt, and which is kept suspended above the mud by a round piece of cork. The forcing-pump drives the water thus drawn up through a leathern pipe into the engine, and renders the laborious conveyance of water by buckets unnecessary.

At first, indeed, this machine was exceedingly simple. It consisted only of a leathern pipe screwed to the engine, the end of which widened into a bag supported near the reservoir, and kept open by means of a frame, while the labourers poured water into it from buckets. A pump, however, to answer this purpose was soon constructed by the Van der Heides, who named it a snake-pump. By its means they were able to convey the water from the distance of a thousand feet; but I can find no account of the manner in which it was made. From the figure, I am inclined to think that they used only one cylinder with a lever. Sometimes also they placed a portable pump in the water, which was thus drawn into a leathern hose connected with it, and conveyed to the engine. Every pipe or hose for conveying water in this manner they called a wasserschlange, water-snake, and this was not made of leather, like the hose furnished with a fire-pipe, but of sail-cloth. They announced, however, that it required a particular preparation, which consisted in making it water-tight by means of a proper cement. The pipe also, through which the water is drawn up, must be stiffened and distended by means of metal rings; otherwise the external air, on the first stroke of the pump, would compress the pipe, so that it could admit no water. It is here seen that pipes made of sail-cloth are not so new an invention as many have supposed. That our present apparatus for conveying water to the fire-engine is much more ingenious, as well as convenient, must be allowed; but I would strongly recommend that in all cities there should be pumps, or running wells of water, to the spout of which pipes having one end screwed to a fire-engine might be affixed. The Van der Heides, among the advantages of their invention, stated that this apparatus rendered it unnecessary to have leathern buckets, which are expensive, or at any rate lessened their number, as well as that of the workmen.

From this account, the truth of which cannot be doubted, one may readily believe that engines with leathern hose were certainly not invented by Gottfried Fuchs, director of the fire apparatus at Copenhagen, in the year 1697, as publicly announced in 1717, with the addition, that this invention was soon employed both in Holland and at Hamburg. Fuchs seems only to have made known the Dutch invention in Denmark, on occasion of the great fire which took place on the 19th of April 1689, at the Opera-house of Amalienburg, when the beautiful palace of that name, and more than 350 persons were consumed. At any rate we are told in history, that, in consequence of this calamity, an improvement was made in the fire establishment, by new regulations issued on the 23rd of July 1689, and that engines on the Dutch construction, which had been used more than twelve years at Amsterdam, were introduced.

Hose or pipes of this kind for conveying water were however not entirely unknown to the ancients. At least the architect Apollodorus says, that to convey water to high places exposed to fiery darts, the gut of an ox, having a bag filled with water affixed to it, might be employed; for on compressing the bag, the water would be forced up through the gut to the place of its destination611. This was a conveyer of the simplest kind.

Among the latest proposals for improving the hose is that of weaving one without a seam. In 1720, some of this kind were made of hemp at Leipsic, by Beck, a lace-weaver, as we are told by Leupold, in his before-mentioned work on fire-engines, which was printed the same year. After this they were made by Erke, a linen-weaver of Weimar; and at a later period they were made of linen at Dresden, and also in Silesia612. In England, Hegner and Ehrliholzer had a manufactory at Bethnal-green, near London, where they made water-tight hose without seams613. Some of the same kind are made by M. Mögling on his estate near Stutgard, on a loom of his own invention, and are now used in many towns of the duchy of Wirtemberg. I shall here remark, that Braun had a loom on which shirts could be wove without a seam, like those curious works of art sometimes brought from the East Indies, and of which he has given a full description with an engraving614.

In the last place, I shall observe, that notwithstanding the belief of the Turks in predestination, fire-engines are in use at Constantinople, having been introduced by Ibrahim Effendi.

[The fire-engines now in use are made upon the air-chamber principle above-described. Mr. Braithwaite has applied steam-power to the working of fire-engines. On this principle a locomotive and a floating engine have been constructed. The former was first employed at a fire in the Argyle Rooms in 1830. It required eighteen minutes to elapse before the water in the boiler was raised to 212°, and threw up from thirty to forty tons of water per hour, to a height of ninety feet. Two others have been constructed by the same engineer, one of which threw up ninety tons of water per hour, and one made for the king of Prussia threw up about 61¾ tons per minute. In the steam floating engine which lies in the Thames, the machinery either propels the vessel, or works the pumps as required. The pipes used for conveying the water from the plugs to the engines are now constructed of leather, the seams being either sewed up or fastened with metallic rivets.]

INDIGO

It is more than probable that indigo, so early as the time of Dioscorides and Pliny, was brought to Europe, and employed there in dyeing and painting. This I shall endeavour to show; but under that name must be understood every kind of blue pigment, separated from plants by fermentation, and converted into a friable substance by desiccation; for those who should maintain that real indigo must be made from those plants named in the botanical system Indigofera tinctoria, would confine the subject within too narrow limits; as the substance which our merchants and dyers consider as real indigo is prepared, in different countries, from so great a number of plants, that they are not even varieties of the same species.

Before the American colonies were established, all the indigo employed in Europe came from the East Indies; and till the discovery of a passage round the Cape of Good Hope, it was conveyed, like other Indian productions, partly through the Persian Gulf, and partly by land to Babylon, or through Arabia and up the Red Sea to Egypt, from which it was transported to Europe. Considering this long carriage, as the article was not obtained, according to the Italian expression, a drittura, that is, in a direct manner, it needs excite no surprise, that our knowledge, in regard to its real country and the manner of preparing it, should be exceedingly uncertain and imperfect. Is it astonishing that articles, always obtained through Arabia, should be considered as productions of that country; and that many commodities which were the work of art, should be given out to be productions of nature? For more than a hundred years the Dutch purchased from the Saxons cobalt, and smalt made from it, and sold them again in India; and the Indians knew as little where and in what manner the Dutch obtained them, as the Saxons did the people who were the ultimate purchasers and consumers. The real nature of indigo was not generally known in Europe till the Europeans procured it from the first hand; yet long after that period, and even in the letters-patent obtained on the 23rd of December 1705, by the proprietors of the mines in the principality of Halberstadt and the county of Reinstein, indigo was classed among minerals on account of which works were suffered to be erected; but this only proves the individual ignorance of the undertakers, and also of their superiors, when they read what they had written, and confirms the justness of Ovid’s advice,

Disce bonas artes, moneo, Germana juventus;

Non tantum trepidos ut tueare reos.

What Dioscorides calls Indicon, and Pliny and Vitruvius Indicum, I am strongly inclined to believe to have been our indigo615. It was a blue pigment brought from India, and used both in painting and in dyeing. When pounded it gave a black powder, and when suspended in water it produced an agreeable mixture of blue and purple. It belonged to the costly dye-stuffs, and was often adulterated by the addition of earth. On this account, that which was soft without any roughness, and which resembled an inspissated juice, was esteemed the best. Pliny thinks616 that pure indigo may be distinguished from that which is adulterated by burning it, as the former gives an exceedingly beautiful purple flame, and emits a smell similar to that of sea-water. Both he and Dioscorides speak of two kinds, one of which adheres to reeds, in the form of slime or scum thrown up by the sea; the other, as Dioscorides says, was scraped from the sides of the dye-pans in the form of a purple-coloured scum; and Pliny expressly remarks, that it was collected in this manner in the establishments for dyeing purple. The former relates also, that Indicum belonged to the astringent medicines; that it was used for ulcers and inflammations, and that it cleansed and healed wounds.

This is all, as far as I know, that is to be found in the works of the ancients respecting Indicum. I have given it at full length, as accurately as possible, and I have added, in order that the reader may be better able to compare and judge, references to the original words of the authors. Indicon, it is true, occurs in other passages; but it was certainly different from the one already mentioned. I allude, for example, to the black Indicon of Arrian and the Indicon of Hippocrates. Of the former I shall treat in particular hereafter; and in regard to the latter, I refer to the author quoted in the note below617. It is not at all surprising that these names should be applied to more Indian commodities, since at present we give to many kinds of fruit, flowers, fowls and other things, the appellation of Indian. The ancients, indeed, were not so careful as to distinguish always, by a proper addition, the many articles to which they gave the name of Indica; and they had reason to expect that their contemporaries would readily comprehend by the connexion, the kind that was properly meant. Their commentators, however, in later times have for the most part thought only of one species or thing, and by these means they have fallen into mistakes which I shall here endeavour to rectify.

Everything said by the ancients of Indicum seems to agree perfectly with our indigo. The proper country of this production is India; that is to say, Gudscharat or Gutscherad, and Cambaye or Cambaya, from which it seems to have been brought to Europe since the earliest periods. It is found mentioned, from time to time, in every century; it is never spoken of as a new article, and it has always retained its old name; which seems to be a proof that it has been used and employed in commerce without interruption.

It is true, as the ancients say, that good indigo, when pulverized, is of a blackish colour. The tincture, however, is partly blue and partly purple; but under the latter term we must understand an agreeable violet, and not, as is often the case, our scarlet. It is true also that good indigo is soft or smooth to the touch618 when pounded; it floats on water, and at present, as in the time of Pliny, is adulterated and rendered heavier by the admixture of some earth, which in general, as appears, is fine pounded slate619. It is further true that the purity of it can be discovered by burning it. Indigo free from all foreign bodies leaves but little ash, while that which is impure leaves a large quantity of earth. Pliny, perhaps, did not rightly understand this test by fire, and added from conjecture, what he says in regard to the colour of the flame and the smell of the smoke, that this proof might not remain without an explanation. It is, however, possible that those who considered indigo to be sea-slime, imagined that they perceived in it a smell of sea-water. A naturalist of modern times, who refers petrifactions to Noah’s flood, believed that he could smell sea-water in them after the lapse of so many thousand years.

Indicum, on account of its long carriage by land, must have been dear, and therefore it was one of those pigments which the ancient painters, who were often poor slaves, were not accustomed to keep in any quantity by them, and with which it was necessary they should be supplied by those for whom they executed paintings620. Our indigo was also exceedingly dear till it was cultivated in the West Indies, where the value of it decreased as long as good land was plentiful and the price of labour was lessened by the slave-trade.

That indigo, which at present is used only by dyers, should have been employed also for painting, needs excite no surprise. It was applied to this purpose till the invention of painting in oil, and the discovery of Prussian blue, smalt and other pigments of a superior quality. It is even still used by landscape-painters to produce a pale gray; but it will not harmonise with oil. As to the medical properties of indigo, I can at any rate show that the experiments made with it at the end of the seventeenth and the beginning of the eighteenth century fully confirm the high encomium bestowed by Dioscorides upon his Indicum. There was a time when the former was much prescribed and recommended. At present our physicians are acquainted with purer and more powerful remedies than indigo, the internal use of which, as the fermented mass is prepared in copper vessels, must be attended with suspicion.

That the author, so often mentioned already, was not acquainted with the preparation of indigo, cannot be denied. It would, indeed, have been extraordinary had the account of it reached the Greeks and the Romans undisguised by fables, added either to answer the purposes of the interested merchant, or accidentally in the course of its long journey, in passing through so many countries and languages. It appears to me, however, that through these it may still be discovered; and in all probability we should be better able to form some idea of it were the oldest method of making indigo still known. In the slime deposited on the reeds, I think I can remark the first degree of fermentation, or commencement of putrefaction, without which the pigment could not be separated. Who knows whether the indigo plants in the earliest times were not deposited in pits or in stagnant water, in the same manner as our flax and hemp? Who knows whether after putrefaction they were not taken out, and the colouring parts adhering to them washed off and collected? The quantity indeed obtained by this process would not be great, and at present a much better method is employed; but the improvements made in every art have been gradual. The old inhabitants of the Canary islands scratched their land with the horns of oxen, because they were not acquainted with the spade, and far less with the plough. The above conjecture will appear much more probable, when it is known that in many parts of India the plants were formerly placed in large pits; and in Malta, where indigo was still cultivated in the seventeenth century, they were put into reservoirs or basins in order to ferment621. If this was usual in the oldest times, it may be easily seen how fabulous accounts might arise. Indigo was a slime attracted from the water by a reed, which the indigo plant, stripped of its bark, was considered to be.

Dioscorides speaks of another kind of indigo, which was the dried purple-coloured scum of the dye-pans. My predecessors, considering this account as an error, which might have arisen either from conjecture or misconception, or which was purposely occasioned by merchants, did not think it worthy of further examination. I cannot, however, refrain from remarking, that a blue pigment, and even a very fine one, if the proper preparations had been made for that purpose, might have been obtained in this manner. It was not indeed indigo, in the proper sense of the word, but a pigment of a similar nature. That fine high-priced powder sold, at present, under the name of blue carmine, is made from the separated scum of a dye-liquor, in which the finest colouring particles remain suspended. The scum or flower of a blue pan622 which floats on the surface exhibits a play of many colours; and as among these the ancient purple is frequently observed, it may therefore very properly be said to have a purple colour623. In my opinion, there is no reason to disbelieve Dioscorides, when he says that in his time a blue pigment named indigo was made in this manner, especially as it can be proved that the woad-dyers, at the end of the sixteenth century, separated from their pans a colouring substance, which they sold instead of indigo, an article at that time exceedingly dear624. Besides, we read that in the establishments for dyeing black, the scum was in like manner collected in old times in the form of a black pigment, and this practice, as appears, was usual in all the dye-houses in general. Pliny, who says that this indigo was made in the purple dye-houses, seems either to have misunderstood Dioscorides, or to have been too precipitate; but it is certain that the scum in the purple dye-houses may have been collected and dried into a purple-coloured carmine.

As the Europeans did not become acquainted with the nature of indigo till modern times, it needs excite no astonishment that the old commentators should have erred in explaining the passages to which I here allude; and their opinion can therefore be of little weight in opposition to mine. Those who have approached nearest to the truth, Sarazen, Mathioli, Salmasius, &c., speak as if indigo were made from our woad, which however does not grow in India. Dioscorides speaks also of woad in a particular section. Marcellus Vergilius says, that Dioscorides meant indigo is certain; and this article is so generally known that it is not worth while to mention it. But he himself seems not to have been acquainted with it, else he would have amended the erroneous passage which speaks of Indian stone625. This arose from the ignorance of the old transcribers, who being unacquainted with Indicum thought only of gemma Indica, mentioned by Pliny626. But Vergilius was right in this, that the purple lake, spoken of by Pliny, and not by Dioscorides as he believes, can no longer be produced.

I have long made it a rule, and prescribed it to others, in explaining any object mentioned by the ancients, never to admit, without the strongest proofs, that the same article is denoted by different appellations. This, it is true, has been often done. By these means the small knowledge we possess of a thing that occurs under one name only may be increased. A wider field may thus be opened for conjecture, and more latitude may be given to the imagination; but at the same time one may fall into groundless explanations, and hazard assertions, which, with whatever caution and learning proposed, will, on closer examination, be found either false or highly improbable. According to this rule, I have carefully endeavoured not to suffer myself to be so far misled by the respectability of my predecessors, as to consider the Indicum and Indicum nigrum of the ancients to be the same substance. On further research I find that the latter not only appears by the epithet to be different from indigo, but that it is China, or, as the Dutch call it, Indian ink. To prove this, I must refer to the passage of Pliny627 on which my assertion is founded; and perhaps the short illustrations added will render this minuteness less tedious to those who are fond of such disquisitions. In the passage referred to, Pliny enumerates all the materials which in his time were used for black ink. He therefore mentions two vitriolic substances, a slime or sediment (salsugo), and a yellow vitriolic earth (called also misy). Such minerals continued in use as long as men were unacquainted with the art of lixiviating the salt, and causing it to crystallize; or in other words, as long as they had no vitriol-manufactories. He speaks also of lamp-black being made in huts built for the purpose, which are described by Vitruvius, and from which the smoke of burning pine-wood was conveyed into a close apartment. The article was certainly adulterated, when soot, taken from the baths and other places where an open fire was maintained with wood of all kinds, was intermixed with it. It is very remarkable that black from burnt refuse of grapes, noir de vigne, which at present our artists, and particularly our copper-plate printers, consider as the most beautiful black, was made even at that period. Germany hitherto has obtained the greater part of this article from Mentz, through Frankfort, and on that account it is called Frankfort black. Some is made also at Kitsingen, Markbreit, and Munich. For this purpose the refuse of the grapes is charred in a close fire, and being then finely pounded is packed into casks. Pliny observes, that it was asserted that from this substance one could obtain a black which might be substituted for indigo. Another pigment was bone-black, or burnt ivory, which is highly esteemed even at present. Besides these, continues he, there is obtained from India what is called Indicum, the preparation of which I have not yet been able to learn: but a similar pigment is made from the black scum of the dye-pans, in places for dyeing black, and another kind is obtained from charred fir-wood finely pulverized. The cuttle-fish (sepia) likewise gives a black; but that however has nothing to do with the present question. He remarks, in the last place, that every kind of black pigment is improved, or rather the preparation of it completed, by exposure to the sun628; that is to say, after gum has been added to that intended for writing, and size to that destined for painting. But that which was made with vinegar was more durable, and could not be easily effaced by washing. All this is very true. Our ink acquires a superior quality when exposed to the light of the sun in flat vessels. That vinegar renders black colours faster, is well known to our calico-printers; and those who wish to have good ink must employ in making it the brightest vinegar of beer. It is equally true, that every black pigment mixed up with gum or size can be sooner and easier washed out again with water629.