796 



HEAT-REGULATOR 



according as the temperature of tho water in the bath shall tend more or loss to deviate 

 from the pitch to which tho apparatus has been adjusted. Tho water of the condensed 

 eteam will pass off from the sloping winding-pipe i n o p, through the sloping orifice p. 

 A saline, acid, or alkaline bath has a boiling temperature proportional to its degree of 

 concentration, and may therefore have its heat regulated by immersing a thermostat 

 in it and connecting the working-part of the instrument with a stopcock ', which will 

 admit water to dilute the bath whenever by evaporation it has become concentrated, 

 and has acquired a higher boiling point. The space for tho bath, between tho outer 

 and inner pans, should communicate by one pipe with tho water-cistern in, and by 

 another pipe with a safety cistern r, into which the bath may be allowed to overflow 

 during any sudden excess of ebullition. 



Fig. 1151 is a thermostatic apparatus, composed of three pairs of bars d d d, which 

 are represented in a state of flexure by heat ; but they become nearly straight and 

 parallel when cold, a b c is a guide rod, fixed at one end by an adjusting screw e, in 

 the strong frame/ e, having deep guide grooves at the sides. / g, is the working-rod 

 which moves endways when tho bars d d d, operate by heat or cold. A square 

 register-plate h g, may bo affixed to the rod / g, so as to bo moved backwards and 

 forwards thereby, according to the variations of temperature ; or the rod / g, may 

 cause the circular turning air-register, i, to revolve by rack and wheel work, or by a 



1149 



1152 



chain and pulley. The register-plate h g, or turning register ', is situated at the ceil- 

 ing or upper part of the chamber, and serves to let out hot air. k, is a pulley, over 

 which a cord runs to raise or lower a hot-air register /, which may be situated near tho 

 floor of the apartment or hot-house, to admit hot air into the room, c is a milled head, 

 for adjusting the thermostat, by means of the screw at e, in order that it may regulate 

 the temperature to any degree. 



Fiff. 1152 represents a chimney, furnished with a pyrostat, a b c, acting by the links 

 b, d, e, c, on a damper/ h g. The more expansible metal is in tho present example 

 supposed to be on the outside. The plane of tho damper-plato will, in this case, be 

 turned more directly into tho passage of the draught through the chimney by increase 

 of temperature. 



Fiff. 1150 represents a circular turning register, such as is used for a stove, or stove- 

 grate, or for ventilating apartments ; it is furnished with a series of spiral thormostatic 

 bars, each bar being fixed fast at the circumference of tho circle b, c, of the fixed plate 

 of the air-register; and all the bars act in concert at the centre a of the turning part 

 of the register ; by their ends being inserted between the teeth of a small pinion, or 

 by being jointed to the central part of tho turning plate by small pins. 



Fig. 1149 represents another arrangement of tho thormostatic apparatus applied to 

 a circular turning register, like tho preceding, for ventilating apartments. Two pairs 

 of compound bars are applied so as to act in concert, by means of tho links a c, b c, on 

 tho opposite ends of a short lever which is fixed on tho central part of the turning 

 plate of the air-register. The two pairs of compound bars a b, are fastened to tho cir- 

 cumference of the fixed plate of the turning register, by two sliding rods a d, b c, which 

 are furnished with adjusting screws. Their motion of flexure is transmitted by the 

 links a c and b c, to the turning plate, about its centre, for the purpose of shutting or 

 opening the ventilating sectorial apertures, more or less, according to tho tompenituro 

 of tho air which surrounds tho thermostatic turning register. By adjusting tho screws 

 a d, and b c, tho turning register is made to close all ita apertures at any d 

 degree of temperature ; but whenever tho air is above that temperature, the flexure of 

 the compound bars will open tho apertures. 



