CA1 



CAL 



fed to the bottom, or grating, by 28 pieces 

 of timber on the outside, and 18 within, 

 called straps, about 8 inches broad, and 

 about 3 inches thick, reaching and lapping 

 over the tops of the sides; the lower 

 part of these straps were dove-tailed to 

 the outer curb of the grating, and kept 

 in their places by iron wedges. The pur- 

 pose of these straps and wedges was, 

 that when the pier was built up suffici- 

 ently high above low-water mark, to ren- 

 der the caisson no longer necessary for 

 the masons to work in, the wedges be- 

 ing drawn up gave liberty to clear the 

 straps from the mortices, in consequence 

 of which the sides rose by their own buoy- 

 ancy, leaving the grating under the foun- 

 dation of the pier. The pressure of the 

 water upon the sides of the caisson 

 was resisted by means of a ground timber 

 or ribbon, 14 inches wide and 7 inches 

 thick, pinned upen the upper row of tim- 

 bers of the grating; and the top of the 

 sides was secured by a sufficient number 

 of beams laid across, which also served 

 to support a floor, on which the labour- 

 ers stood to hoist the stones out of the 

 lighters, and to lower them into the cais- 

 son. The caisson was also provided with 

 a sluice, to admit the water. The method 

 of working was as follows : A pit being 

 dug, and levelled in the proper situation 

 for the pier of the same shape of the cais- 

 son, and about five feet wider all round, 

 the caisson was brought to its position, a 

 few of the lower courses of the pier built 

 in it, and sunk once or twice, to prove 

 the level of the foundation ; then, being 

 finally fixed, the masons worked in the 

 usual methods of tide-werk. About two 

 hours before low water, the sluice of 

 the caisson, kept open till then, lest 

 the water, flowing to the height of many 

 more feet on the outside than the inside, 

 should float the caisson and all the stone- 

 work out of its true place, was shut 

 down, and the water pumped low enough, 

 without waiting for the lowest ebb of 

 the tide, for the masons to set and cramp 

 the stonework of the succeeding courses. 

 Then, when the tide had risen to a con- 

 siderable height, the sluice was opened 

 again, and the water admitted ; and as 

 the caisson was purposely built but 16 

 feet high, to save useless expence, the 

 high tides flowed some feet above the 

 sides, but without any damage or incon- 

 venience to the vrorks. In this manner 

 the work proceeded till the pier rose to 

 the surface of the caisson, when the 

 sides were floated away, to serve the same 

 purpose at another pier. 



CAKILE, in botany, sea-rocket, a genuj 

 of the TetrandriaSiliculosa class and order. 

 Silicic lanceolate, somewhat four-sided, 

 consisting of two deciduous joints, with- 

 out valves, and each containing a single 

 seed : the lower joint with a tooth on 

 each side at the lip. There are two 

 species, viz. C. maritima, found on the 

 sea-coast of England ; C. JEgyptiaca, a 

 native of Italy and Egypt. 



CALAGUALA root, brought from A- 

 merica for medicinal purposes, and has 

 acquired considerable reputation on the 

 continent. It is supposed to be obtained 

 from a species of poly podium. Its colour 

 is brown, and partly covered with scales, 

 like the roots of fern, and is hard and 

 difficult to reduce to powder. It is as- 

 serted by Vauquelin that it contains 



Colouring matter 

 Malic acid 



Woody fibre 



Gum 



Resin Muriate of potash 



Sugar Lime 



Starch Silica. 



The mode of analysis may be thus de- 

 scribed. Alcohol dissolves the resin and 

 sugar. By evaporating the solution to 

 dryness, and treating the residue with 

 water, the sugar is separated, and the 

 resin left. Water dissolved the gum and 

 the muriate of potash, which were ob- 

 tained by evaporation. Diluted nitric 

 acid dissolved the starch and colouring 

 matter, and let fall the former, when 

 mixed with four times its bulk of alco- 

 hol. The woody fibre remained, which, 

 when incinerated, left carbonate of lime, 

 muriate of potash, and a little silica. As 

 the decoction reddened vegetable blues, 

 it is possible that the lime was in com- 

 bination with malic acid. 



CALAMANCO, a sort of woollen stuff 

 manufactured in England and in Brabant. 

 It has a fine gloss, and is chequered in 

 the warp, whence the checks appear only 

 on the right side. Some calamancoes are 

 quite plain, others have broad stripes 

 adorned with flowers ; some with plain 

 broad stripes, some with narrow stripes, 

 and others watered. 



CALAMARLE, in botany, the name of 

 a third order in Linnaeus's " Fragments 

 of a Natural Method." This order will 

 be easily distinguished from the family of 

 grasses, by recollecting, 1. That the base 

 of the leaf, which embraces the stalk like 

 a glove, has no longitudinal aperture in 

 plants of this order, but is perfectly en- 

 tire : 2. The stalk is generally triangular, 



