670 



BLOWING-MACHINE BLOW PI I'E. 



emits which he actually witnessed. Hence there is 

 H degree of spirit and originality in (In- poem. \vliicli 

 < .n>(>s it \vitli the impress of eniu*, rind renders ii 

 very pleasing. Tin- versification is uncommonly 

 -month and correct. B. also wrote ;i > olumc entitled 

 \Vikl Flowers, containing a collection of poetical 

 tales, which was well received, and was not unworthy 

 of his reputation. II is latent production was Hazel- 

 wood Hall, a village drama, which appeared shortly 

 before his dciv.iM-, a work of not much merit. 1$. was 

 patronized liy the dukr of (ir.ifion, who bestowed on 

 n iin a small annuity, and made him an under-sealer 

 i i the seal-office. This situation he was forced to 

 re sign on account of ill health. He then worked again 

 nt his trade, as a shoemaker, and employed himself 

 in constructing .Eolian harps. Engaging in the book 

 trade, In- hi-came a bankrupt, and, in the latter part 

 of his life, was afflicted with violent head-aches, and 

 became nearly blind. He was gradually reduced to 

 such u state of nervous irritability, that apprehensions 

 were entertained of his becoming insane. These 

 fears were terminated by his death, which took place 

 in August, ISsM. 



BLOWING-MACHINE; an engine employed at iron 

 works and oilier places, for supplying large furnaces 

 with a blast of air. It is necessary that the current 

 of air should be propelled into the furnace with a cer- 

 tain rapidity, volume, and also with regularity ; for 

 which purposes many contrivances have been em- 

 ployed. The best form of the machine is represent- 

 ed in the cut below. Where C is a hollow cylinder 

 furnished with a piston E, similar to that of a common 

 steam engine. The piston-rod D, works through a 

 stuffing box at the top of the cylinder, also similarly 

 formed with that of the steam engine. A and B are 

 pipes leading into the cylinder, and furnished with 

 valves opening inwards. On the opposite side of the 

 cylinder are two valves F and G, opening outwards 

 from the cylinder into two pipes, which lead into the 

 large upright pipe H. From this pipe, which is 

 closed both at bottom and top, there proceeds a pipe 

 PO, a branch of which leads off at I, into the iron 



chest K, which has no bottom, but rests in a cistern 

 of water, a part of the stone work of the sides of 

 which is seen at M and N. Above this branch there 

 is a valve L opening upwards. The figure will now 

 be completely understood by following the operation. 

 When the piston is at the bottom of the cylinder, and 

 is then raised, the valve A will shut, and all the air 

 will in a condensed state be forced through the valve 

 G into the pipe H. During the ascent of the piston, 

 8 vacuum would be formed in the cylinder below the 

 piston, in consequence of which the valve F would 

 be shut, and the valve B open, which last admits the 

 air into the cylinder C. When the piston begins to de- 

 scend, the condensation of the air within the cylinder 

 will cause the valve B to shut and F to open, so that 

 the condensed air will rush into the pipe H ; and 

 by the alternate ascent and descent of the piston, the 

 air in a.compressed state is sent into the pipe H. The 

 compressed air proceeds along the pipe PO, but as 

 the branch I allows it a passage into the chest K, it 



will press upon the surface of the water in the cis- 

 tern, and of course cause it to rise on the outside of 

 the chest, to the height of eight feel above the level 

 of the water in the chest. By this contrivance, should 

 there be any intermission in the intensity of the blast, 

 the column of water in the cistern will press up the 

 air in the chest, and thus equalize the current above. 

 The valve at L is loaded with a certain pressure, so 

 that when the engine is going too quick, and the 

 supply of air too rapid, the valve will be forced open. 

 Two branches are led from the horizontal pipe at <>, 

 one to each side of the furnace. It has been found 

 that the same bulk of air at 32", has ten per cent, more 

 oxygen than at 85 when dry, and if s^unv.u d with 

 moisture, twelve per cent. ; wherefore, if 1500 cubic 

 feet per minute be a sufficient supply in winter, I c .. . 

 will be required in summer, to have the same effect. 

 From this it was inferred, that the colder the blast, 

 the greater would be the effect ; but at the Clyde 

 iron works, and other founderies, the pipe which con- 

 ducts the compressed air from the chest to the fur- 

 nace is made to pass through the fire, and the air is 

 thus heated to a very high temperature before it acts 

 upon the fuel. See Grier's Mech. Diet. 



BLOWPIPE is the name applied loan instrument, by 

 means of which the flame of a candle or lamp is made 

 to produce an intense heat, capable of being applied 

 to a variety of useful purposes. Its most simple form 

 is that of a tapering tube, about eight inches in 

 length, and curved nearly at right angles, within two 

 inches of its smaller extremity. At its larger end, it 

 is nearly a quarter of an inch in diameter, and at the 

 smaller, only large enough to admit a common-sized 

 pin. It is made of brass or white iron. In using it, 

 the flame of a lamp or candle is turned aside from its 

 vertical to a horizontal direction, by a stream of air 

 impelled upon it, either from the lungs or from a 

 double bellows. The flame, in its new direction, as- 

 sumes a conical shape, and consists of two parts, 

 visible by their different colours ; the outer being 

 reddish-brown, and the inner blue. The heat at the 

 apex of the inner cone is the most intense, and is 

 equal to that produced in the best furnaces. It is 

 employed by the jeweller and goldsmith in the opera- 

 tion of soldering, and by other artists who fabricate 

 small objects in metal ; by the glassblower in making 

 thermometers, barometers, and other glass instru- 

 ments ; by the enameller, and, indeed, wherever it is 

 required to subject a small body to a strong heat. 



The common blowpipe has undergone a variety of 

 improvements in the hands of the chemist, to whose 

 researches it has proved an excellent auxiliary. Fig. 

 16, plate IX., represents the common blowpipe, be- 

 ing simply a tapering brass tube, having the smaller 

 end, from which the stream of air is transmitted to 

 the flame, curved so that the jet shall be sent 

 side wise to the operator. Fig. 12, represents the 

 portable blowpipe of Wollaston , it consists of three 

 pieces fitted into one another, when in use, but which 

 may be taken down, and made to slide within each 

 other, and carried within the pencil case of a common 

 pocket-book. Fig. 13, represents a blowpipe having 

 a hollow bulb near the end, the object of which is to 

 condense the vapour of the breath, which often proves 

 injurious in the common form of the instrument. To 

 prevent corrosion from the action of the moisture, the 

 bulb is made either of silver or sheet tin, and it is 

 capable of being opened, in order that it may be 

 more easily cleaned. A little practice is necessary 

 to enable the operator to keep up a constant blast for 

 any length of time, the current of air being propelled 

 through the pipe by the muscular exertion of the 

 cheeks, while respiration is carried on through the 

 nose. But when the process has to be long continu 

 ed, even the operator of experience wfll find thi? 



