F1L 



F1L 



been employed in different countries for 

 the same uses. In some parts of Sweden 

 a strong cloth is said to have been pre- 

 pared from the stalks of hops. These 

 have been tried here, but without suc- 

 cess. Vegetable filaments, and the thread 

 or cloth prepared from them, differ re- 

 markably from wool, hair, silk, and other 

 animal productions, particularly in their 

 disposition to imbibe colouring matters ; 

 Sundry liquors, which give a beautiful and 

 durable dye to those of the animal, 

 giving no stain at all to those of the vege- 

 lable'kingdom. See DYEING. 



FILARIA, in natural history, a genus 

 of the Vermes Intestina class and order. 

 Body cylindrical, filiform, equal, and quite 

 smooth ; mouth terminal, more or less 

 perceptible, simple, with a roundish con- 

 cave lip. There are about 18 species, 

 divided into four sections : viz. A. infest- 

 ing the mammalia ; B. infesting birds ; C. 

 infesting insects in their perfect state ; D. 

 infesting the larvae of insects. F. medi- 

 nensis is found both in the East and West 

 Indies, and is frequent in the morning 

 dew, from which it enters the naked feet 

 of the slaves, and creates the most trou- 

 blesome itching, frequently accompanied 

 with inflammation and fever. There is 

 great difficulty in extracting it from its 

 hold ; the only method is, by cautiously 

 drawing it out, by means of a piece of silk 

 tied round its head ; for if, by being too 

 hasty, the animal should break, the part 

 remaining under the skin grows with sur- 

 prising vigour, and occasions an alarm- 

 ing, sometimes a fatal inflammation. It 

 is frequently 12 feet long, and not larger 

 than a horse-hair. 



FILBERT, the fruit of the corylus, or 

 hazel. See CORYLUS. 



FILES, manufactory of. Many useful 

 tools have been invented for performing 

 mechanical operations, which consist of a 

 number of wedges or teeth, which may 

 be conceived to stand upon, or rise out 

 of, a flat or curved metallic surface. When 

 these teeth are formed upon the edge of 

 a plate, the instrument is called a saw ; 

 but when they are formed upon a broad 

 surface, it constitutes what is known by 

 the name of a file. The comb-makers and 

 others use a tool of this description, call- 

 ed a quonet, having coarse single teeth, to 

 the number of about seven or eight in an 

 inch. Fine tools of the same kind, name- 

 ly, with single teeth, are called floats. 

 When the teeth are crossed, they are 

 called files ; and when, instead of the 

 notches standing in a right line, a num- 

 ber of single individual teeth are rais- 



ed all over the surface, it is called a rasp. 

 As the art of making files is nearly the 

 same in its practice with regard to all the 

 great variety of forms in which they are 

 made, we shall confine our description to 

 that-of the flat file. 



Very little need be said in explanation 

 of the method of forging these articles. 

 They are usually made of steel, or more 

 rarely of iron, cuse hardened. The forg- 

 ed files are brought to a flat surface on 

 the grindstone, and are then ready for 

 the file-cutter. This artist is provided 

 with a great number of chissels, consisting 

 each of a piece of steel of moderate thick- 

 ness, having a straight edge of greater 

 length than the height of the chissel, the 

 back of which terminates in a blunt angle 

 or point in the middle of its length, upon 

 which the blows are struck with a ham- 

 mer of about five or six pounds weight, 

 for middling sized files, having its head 

 all on one side of the stem, so as to re- 

 semble the capital letter L, in order that 

 it may by its own weight naturally dispose 

 itself with the face downwards. The file 

 is placed upon a plate of lead on a small 

 low anvil, close to which the workman 

 sits, and on the left side of the block 

 of the anvil are fastened the two ends of 

 a leather strap, which he brings over the 

 file, and by putting his right foot into the 

 loop holds it steadily in its place. la 

 this situation., taking the chissel between 

 his left finger and thumb, he applies iis 

 edge across the file, where the cuts 

 are to begin at the point, and gives it 

 a blow ; the direction of the cut being 

 inclined towards the tang, or that end 

 of the file which is to go into the han- 

 dle. Immediately after this commenc- 

 ing operation, he lifts the chisel, 

 places its edge behind the other cut, 

 and slides it forward till he feels it bear 

 against the bur or protuberancy of the 

 former cut, at which instant he gives the 

 second blow ; a third is repeated in like 

 manner, and by a continuance of the same 

 proceeding, the whole surface at length 

 becomes covered with single strokes or 

 notches, each of which presents an ele- 

 vated sharp edge. The distance between 

 stroke and stroke, or, which is the same 

 thing, the coarseness of the file, depends 

 entirely upon the violence of the blow, 

 by which the bur is raised to a greater or 

 less height ; but it is not difficult with so 

 weighty a hammer, after a very little prac- 

 tice, to give the strokes with great unifor- 

 mity of impulse, and to repeat them with 

 such frequency, as to perform this appa- 

 rently delicate work with great speed and 



