VENTILATION. 



287 



We, however, were informed by Mr 

 Fleming, that the whole was made by the 

 village blacksmith, and that he executed 

 his work so well that the apparatus 

 wrought to perfection upon the first trial. 



Fig. 383. 



a be 



The drawings, and reference to them, we 

 copy from "The Gardeners' Chronicle." 

 Fig. 383 — a front section of pulley and 

 rollers ; b front plate lifted off to show 

 the working of the pulleys and rollers ; 



c end section of pulley and rollers. Fig. 

 384 — d toothed wheel and wrench ; e 

 iron rope and pulley for the sinker under 

 ground ; / / horizontal bar, with annealed 

 iron ropes attached. By this contrivance, 

 (the invention of Mr Fleming,) the whole 

 extent of a large house may be ventilated 

 to the greatest nicety „ by merely turning 

 a wrench, which we found no difficulty 

 in doing with one hand. The movement, 

 instead of being vertical, is horizontal — 

 the sashes being attached to an iron bar 

 by annealed iron ropes moving in that 

 direction. The movement is effected by 

 means of a toothed wheel and wrench, 

 the horizontal bar having about 4 feet of 

 its lower edge toothed to suit the wheel. 

 Small rollers are fixed about 6 feet asun- 

 der, and in pairs — one under and another 

 above the bar, to lessen friction. The 

 iron wire ropes that move the sashes up 

 and down are, by means of a pulley, made 

 to turn from the inclined plane to the 

 perpendicular of the back wall ; and, by 

 another pulley, to turn again to the hori- 

 zontal line of the sliding horizontal bar. 

 The ropes are attached to studs, 3 inches 

 long, fixed in the iron bar. Provision is 

 made for lessening the strain on the 

 machinery by having a sinker (h) under 

 ground, {g being the level of the floor,) 

 made fast to the lower edge of the hori- 

 zontal bar by means of an iron rope and 



Fig. 384. 



/fr—ffl/g m izg Ha ®? @\/? SLe 



t§j g igj 151 igr 



pulley. We imagine that the sashes are 

 furnished with brass or iron rollers, to 

 facilitate their moving up and down the 

 rafters. These, however, we should 

 observe, are built at a pretty high angle 

 of elevation, which renders the movement 



of the sashes much easier than if they 

 were more flat. 



In most of the hothouses in the gar- 

 dens at Dalkeith, every alternate top 

 sash is made to slide down the rafters — 

 being furnished with brass castors or 



