Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/403

 SAL

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fait, than the fea water, and being the real produce of fait {brings, with which the whole ifland abounds at a certain depth. In moderate feafons, the failors find thefe pits read) filled with brines, but in times of great drought, they are obliged to dig little wells to come at the water, and with this they fill the pits to the proper depth. The bottom of thefe pits is a kind of clofe earth, which retains the water, and the failors, who firft arrive at the place, clean out as many of thefe as they have occafion for, and others, who follow' them, do the like. After the pits are properly filled, the heat of the fun exhales the water very frefh, and leaves all the fait, which forming itfelf into cryftals, finks to the bottom from time to time. As this is done very quick in this feafon, they twice a week draw out all the fait that is ready formed with rakes, and lay it in little heaps to drain ; after this they add it to their general cargo in one large heap, where it foon dries entirely, and becomes fit to be put on board their flaps.

If the weather be favourable, a large fhip may he, in this manner, loaded with fait in a fortnight, and it is often done much fooner, the failors finding the pits, at their arrival, ready filled with concreted fait.

Though a fhip be thus vefy eafily loaded with fait in good feafons, yet bad weather, and delays upon the voyage, often are the occafion of fhips returning without their loading for the wet deftroys all the fait they had prepared, and the tornados tofs up the fand, and mix it with the fait, and at the fame time make it impofltble to load it. This trade might therefore be carried on with much greater advantage. _ if there was a Britifh factory eifablifhed at the place, whoft bufinefs it mould be to make fait in the dry feafon, and fell it afterwards to the failors, and this might be done at a cheaper rate, than what the feamen can make it for, it ufually {landing them in about fixpence a bufhel. The fait is made at Bonavifta in the fame manner as in the ifland of May ; but the brine is weaker, and the fait does not kern, as the failors call it ; that is, it does not granu- late, or cryftallize, fo foon as in the other place ; but tht fhips are often forced to be contented with this, when either the ifle of May Is too crouded, or when the rainy feafon fets in there, while they are at work; for though thefe if- lands are but eighteen leagues diftant from one another, the rains are fometimes feveral weeks later in one than in the other. The weather is not exceflively hot in either of thefe iflands, the failors finding it tempered continually by breezes from the fea. Brownrig of Salt, p. 26. The Britifh colonies in America have alfo, for near a cen- tury pad, been ufed to fupply themfelves with fait of this kind from Tortuga, one of the Leeward iflands, uninhabited, and fituated near the coafl of Caraccas, on the Spanifh main, and the Turk's ifland, which lies not far from Hifpaniola ; and many veffels, freighted from North-America to Barba- does, and others of the Caribbee iflands, were accuftomed to go from thence to thefe fait iflands, and carry back a loading of fait, for which they always found a market in Newfoundland, New-England, and other places in North- America. The Spaniards, who had been ufed to fuffer this without moleftation, at length feized fuch fhips as they found loaded with this fait, and the traders in this way were compelled to go in a fort of fleet from Barbadoes, and the neighbouring places, and they kept together till out of danger. The method of making the bay fait in thefe places, is much the fame with that already defcribed ; only in the American ifles they do not collect: it out of fmall pits, but out of large ponds and lakes ; and the failors often find vafl quantities of clean and good fait ready prepared, lying at the bottom of thefe lakes.

It has been reported, as a very extraordinary thing, that in thefe American iflands the^ fait never kerns, or forms into grains, except during the hot feafon of the year ; but this is a ftory much improved in the telling, and the whole truth fecms to be this. During the conftant rains, the ponds overflow, and great quantities of fit are wafhed away; and when thefe are over, the ponds and lakes remain full of a very weak brine, fo that no fait can cryftallize in them till moff of the water is exhaled, and this does not happen, till toward the time of the rainy feafon's fetting in again ; but as this feafon begins only in mowers once in two or three days, and thofe not great, the fait is eafily prepared from the brine of the pits, which is then very rich, not- withffanding this flight interruption. Thefe firft mowers of the rainy feafon are always a fort of tornados, and waih off a great quantity of fait from the furface of the earth into the ponds ; and, in general, while they are fo moderate, that there falls no more water in them, than is daily evaporated by the fun, they are an advantage in keeping the ponds fupplied, which otherwife, after the continuance of heat that has been at that time, would be dry, and in no condition for working.

Bay filts, prepared in France and other parts of Europe, are of the fame kind, in the general meaning of the pro- cefles, with thofe of the African and American iflands. As the fait is there prepared from the water of fait fprings, it is in Europe made from fea water. Bay fait is not extracted I Suppl. Vol. II, '

from fea water, in the colder parts of Europe, as on the coafts of Germany, Denmark, and Sweden, but in places fituated in a more fouthern climate, as on the coafts of France, Spain, and Italy. Some marine hay fait has alfo, of late years, been made in England at Limington, and in fome other parts of Harnpfhire, and in the Ifle of Wight: but in thefe places it is only made in drier fummers, and then rather by accident than defign, it being collected from ponds, which were originally made for heightening of fea water, or reducing it into a ftrong brine by the heat of the fun, in order to leffen the expence of fuel, in boiling it into white falts. Brownrig of Salt, p. 35. The ponds, in which this fait is mad.-, nearly refembie a rude kind of fait marfh, defcribed by Agricola, in which the fea water is received into a pool, and thence, by a trench, is conveyed into feveral pits dug in the earth ; and when it has flood fome time in thefe pits, it is fuffered to run out into others, and fo on, till the brine is ftrong enough to cryftallize.

This is the cafe in our Englifh fait works ; but the French marfhes, in which a vafl quantity of bay fait is annually prepared, are made in a much more artful manner. A full account of which is given in the Philofophical Transactions, N° 51. See SALT-mar/b, infra.

When rainy weather happens, in the time that the French are making this fait, they keep it out of the pits as much as puffible ; but unlefs it rain much, the da- mage is not very great, the heat of the fun fufhciently ex- haling it. If it rain very violently for a whole day, all the care in the world cannot fo well keep it out, as to render it practicable to make fait for the three or four next days. But when it has rained fuccefflvely for five or fix days, they are forced to empty all the water out of the beds, and take in frefh, before any fait can be made. This is an ac- cident, however, that rarely happens to them. The hotted years always afford, the moil fait. In the very hot weather, there is fait made even in the night ; and it is always ob- ferved, that there is more fait made in ftormy weather than in calm. The weft, and north-weft winds, aie always found to be moff ufeful to the fait makers ; and in good feafons, the French fait workers chaw out the fait from their pits every other day, and draw more than an hundred weight from every pit. This they do with inftruments that will retain the fait, and are pierced full of fmall holes, which let the water run off.

Thofe pits which are made in a reddifh earth, are always found to' make the fait more grey; and thofe in a bluifh earth, more white; and it is always obferved, that if more than the proper quantity of water be let in, the fait is the whiter, but there is the lefs of it in proportion. All the marfhes fhould have a clayey vifcid earth, neither fpungy nor fandy. There is a great deal of caution to be ufed in drawing out the fait, that the earth, or other impurities of the pit, do not mix with it ; for two workmen, who are differently fkilled in their bufinefs, will procure from the fame pit a very brown and foul, and a very clean and white fait; and they always feparate a pure and white fait, which rifes to the top of the water, before the other granulates, and falls to the bottom. This pure fait is not only of a better colour than the other, but is in fmaller grains, and this is what the politer people ufe at their tables. Thefe marines are overflowed once a year, at the end of the fea- fon, about a foot high, and this preferves them from year to year. Brownrig of Salt, p. 44.

The French have fo many works of this kind, that in fa- vorable feafons as much bay fait is made in a fortnight, as ferves for the whole year, not only for the home confumpti- on, but for that of other nations, who purchafe it of them, and who ufe much more of it than the French themfelves. But, on, the contrary, when a rainy feafon comes, there is often a fcarcity for a whole year afterwards. It is wonder- ful, that though the method in which the French work has been long known among us, we have never attempted it our- felves, either here, or in our American colonies, which would feem a very eafy matter, the principal care being in the firft erecting the works, or fait marfhes. See Salt ?narjh, infra.

The feveral kinds of bay fait, mad': in the different parts of the world, are found to differ greatly from one another in feveral particulars; as r. in the fize of the cryftals, which is owing to the heat of the fun, and the time it lies in the pits. The French cream of fait, and the blown fait of the ifle of May, are fine and fmall grained. The Portugal fait is larger grained than that of France ; and that of Tortuga is larger than either. 2, In purity. As all bay fait has fome mud, flime, or the like, in the making, and fome kinds are mixed with the bittern fait, or what is called Epfom fait, they are all more white while dry, and more pellucid when nioift, and they differ in colour, according to the earth which makes the bottoms of the pits. Thus fome of the French bay fait is grey, fome reddifh, and fome white, ac- cording as a blue clay has lined the pits, or a red, or white one. 4. Some kinds.of bay felt are more apt to contract a moifture from the air than others : this is fgmettmes owing