ILE 



ILJB 



ttir ; all bodies, at least solid and liquid 

 substances, are equally susceptible of it, 

 and if it has ceased, from a reduction of 

 temperature, it may be renewed by the 

 temperature being again raised. The 

 point of temperature at which the first 

 stage of ignition takes place, or at which 

 bodies arrive at a red heat, appears to be 

 the same in all, and is supposed to be 

 about 800 of Fahrenheit. By raising the 

 temperature, the illumination becomes 

 brighter, and the red light acquires a mix- 

 ture of yellow rays. At length, by still 

 increasing ir, we come to the white heat, 

 which is the highest state of ignition. Ae- 

 riform fluids are not brought into a state 

 of illumination by heat. The phenomena 

 are produced not only by the application 

 of heat, but likewise by friction and at- 

 trition. 



JIB, in naval affairs, the foremost sail 

 of a ship, being a large stay-sail, extended 

 from the outer end of the bowsprit, pro- 

 longed by the jib-boom, towards the fore- 

 top-mast-head. In cutters and sloops, the 

 jib is on the bowsprit, and extends towards 

 the lower mast-head. The jib is a sail of 

 great command with any side wind, but 

 especially when the ship is close-hauled, 

 or has the wind upon her beam ; and its 

 effort in turning her head to leeward is 

 very powerful, and of great utility, parti- 

 cularly when the ship is working through 

 a narrow channel. Jib-boom is a continu- 

 ation of the bowsprit forward, being run 

 out from the extremity in a similar man- 

 ner to a top-mast on a lower-mast, and 

 serving to extend the bottom of the jibs 

 and the stay of the fore-top-gallant-mast. 



JIGGER, in naval affairs, a machine 

 consisting of a piece of rope, five feet 

 long, with a block at one end, and a 

 sheave at the other, used to hold on the 

 cable when it is heaved into the ship, by 

 the revolution of the windlass. This is 

 particularly useful, when either slippery 

 with mud or ooze, or when it is stiff and 

 unwieldy, in both which cases it is very 

 difficult to stretch it back from the wind- 

 , lass by hand, which, however, is done 

 with facility and expedition by means of 

 the jigger. 



ILEX, in botany, holly, a genus ^>f the 

 Tetrandria Tetragynia class and order. 

 Natural order of Dumosee. Rhamni, Jus- 

 sieu. Essential character : calyx four- 

 toothed ; corolla wheel-shaped ; style 

 none ; berry four-seeded. There are 

 sixteen species. This genus consists of 

 small trees or shrubs,with alternate leaves, 

 evergreen, toothed, or thorny ; and axil- 

 lary, many -flowered peduncles. I. aqui- 



folium, common holly, is usually frona 

 twenty to thirty feet in height, though it 

 sometimes exceeds sixty feet; the trunk 

 is covered with a greyish bark, and those 

 trees which are not lopped, or browzed 

 by cattle, are commonly furnished with 

 branches the greatest part of their length, 

 forming a sort of cone. Mr. Millar says, 

 the difference of sexes in the flowers of 

 the holly was first observed by his father. 

 In his garden at Streatham, in Surrey, 

 he had many of these trees, which, be- 

 fore he had possession of the place, were 

 shorn into round' heads : he emancipated 

 them from their slavery, pruned them, 

 and trained up leading shoots. Seeming- 

 ly glad to be released from their shackles, 

 they quickly rewarded him with this 

 discovery concerning the nature of their 

 flowers, which he communicated to the 

 Royal Society. He perfectly recollects 

 having carefully attended to the flower- 

 ing of these trees during several seasons, 

 and having uniformly observed herma- 

 phrodite flowers on some, and male flpw- 

 ers on others: in the former, the anthers 

 were different from those in the male 

 flowers, and appeared to be effete, and 

 there never was a single male flower 

 mixed with the hermaphrodite, or a her- 

 maphrodite with the males, or any flower 

 except the two here described. 



The holly makes an impenetrable fence, 

 and bears cropping well, nor is its ver- 

 dure, or the beauty of its scarlet berries, 

 ever observed to suffer from the severest 

 of our winters. Mr. Evelyn's impregna- 

 ble holly -hedge, four hundred feet in 

 length, nine feet high, and five in diame- 

 ter, has been much celebrated by him- 

 self, Ray, and others. 



The wood of this tree is the whitest of 

 all hard woods, and used by the inlayer, 

 especially under thin plates of ivory. The 

 mill-wright, turner, and engraver, prefer 

 it to any other : it also makes the best , 

 handles and stocks for tools, flails, the 

 best riding rods, and carters' whips;* 

 bowls, chivers, and pins for blocks ; Mr. 

 Millar says it is made into hones for set- 

 ting razors ; that the wood, taking a fine 

 polish, is proper for several kinds of fur- 

 niture ; that he has seen the floor of a 

 room laid in compartments with this and 

 mahogany, which had a very pretty ef- 

 fect. 



It is much used with box, yew, and 

 white thorn, in the small trinkets and 

 other works, carried on in and about 

 Tunbridge, commonly called Tunbridge 

 ware. 



Sheep and deer are fed during 1 the win- 



