784 HAT MANUFACTURE 



and dyes wool or silk mordanted with tho salts of alumina a light rose-red or a doep 

 scarlet. The colours are said to bn fugitive. 



H-aRMA-LIUE. An organic alkaloid extracted from tho seeds of the Pcganum 

 Harmala. A base obtained by the oxidation of harmalino has been called hanniiir. 



HARIVIOTOIVIE. A hydrous silicate of alumina and baryta. This zeolite crys- 

 tallises in the rhombic system, often in twins crossing each other, whence the common 

 name ' Cross-stone.' 



It accompanies lead-ore at Strontian in Argyleshiro, and at Andreasberg in the 

 Hartz. It is also found, with other zeolites, in cavities in amygdaloidal rocks. 



H ARRISITE. A variety of copper-glance, with cubic cleavage ; supposed to be 

 a pseudomorph after galena. 



HARTITE. A hydrocarbon, found in brown-coal near Vienna. 

 HARTSHORN", SPIRIT OF, is the old name for the solution of ammonia in 

 water, the weak Liquor ammonia of the London Pharmacopoeia. 



HASSOCK. A term given to a kind of sandstone occurring in the quarries of 

 Kentish Ragstone in Kent. When of good quality, it .is employed in building the 

 interior walls of churches. The following is an analysis of hassock, by Dr. Plomby, 

 of Maidstone : carbonate of lime, 53 ; alumina, 4 ; oxide of iron, 8 ; silica, 32 ; 

 small quantities of phosphate of lime, soda, magnesia, chlorine and sulphuric acid, 3 : 

 = 100. 



HA.TCHETTIWE. One of the native hydrocarbons. It occurs in the crevices of 

 septaria of clay-ironstone from the coal-measures at EbbwVale, in masses resembling 

 wax. It is also found in Argyleshire. According to Johnston its composition is : 

 carbon, 86'91 ; hydrogen, H'62 : = 100'53. It is also known as mineral tallow. 



HAT MANUFACTURE. (Hart de chapelier, Fr. ; Hutmacherkunst, Gor.) 

 Hat is the name of a covering for the head worn by both sexes, but principally by 

 men. 



As the art of making hats does not involve the description of any curious machinery, 

 or any interesting processes, we shall not enter into minute details upon the sub- 

 ject. It will be sufficient to convey to the reader a general idea of the methods 

 employed in the manufacture of beaver and silk hats. 



The materials used in making stuff hats are the furs of hares and rabbits freed 

 from the long hair, together with wool and beaver. The beaver is reserved for the 

 finer hats. 



The fur is first laid upon a hurdle made of wood or wire, with longitudinal 

 openings ; and the operator, by means of an instrument called the bow (which is a 

 piece of elastic ash, six or seven feet long, with a catgut stretched between its two 

 extremities, and made to vibrate by a bowstick), causes the vibrating string to strike 

 and play upon the fur, so as to scatter the fibres in all directions, while the dust and 

 filth descend through the grids of the hurdle. 



After the fur is thus driven, by the bow from one end of the hurdle to the other, it 

 forms a mass called a bat, which is only half the quantity sufficient for a hat. The 

 bat or capade thus formed is rendered compact by pressing it down with the hardening 

 skin (a piece of half-tanned leather), and the union of the fibres is increased by cover- 

 ing them with a cloth, while tho workman presses them together repeatedly with his 



hands. The cloth being taken off, a piece of 

 paper, with its corners doubled in, so as to give 

 it a triangular outline, is laid above the bat. 

 The opposite edges of the bat are then folded 

 over the paper, and, being brought together 

 and pressed again with the hanjds, they form 

 a conical cap. This cap is next laia upon 

 another bat, ready hardened, so that the joined 

 eges of the first bat rest upon the new one. 

 This new bat is folded over the other, and its 

 edges joined by pressure as before ; so that 

 the joining of the first conical cap is opposite 

 to that of the second. This compound bat is 

 now wrought with the hands for a considerable 

 time upon the hurdle between folds of linen 

 cloth, being occasionally sprinkled with ch-ar 

 water, till the hat is batoned, or rendered 



tolerably firm. 



The cap is now token to a wooden receiver, 



like a very flat mill-hopper, consisting of eight wooden planes, sloping gently to the 

 centre, which contains a kettle filled with water acidulated with sulphuric acid. The 

 technical name of this vessel is the battery. It consists of a kettle A, Jiff. 1 127 ; and 



