MISCELLANY OF NOTES AND CORRESPONDENCE. 143 



woody embrace ; at last the lattei s ™'^ 8 specimens were brought over 



B!ss&wrsi£nss.3MS « '» *- ■*■* '" 



the woods of the tropics. 



On Hating Plant Houses, Pit Frames, &c.-Of late years considerable 

 »H?ntion his been paid to improve the system of heating erections or hort.cul- 

 attentwn has been paiap Much / has been effected to advantage. Very 



in the • hardener's Chronicle," which we extract, to afford our readers an oppor- 

 tunity of what the system is expected to realize. 



rolmaise Heatinq.-A short time ago I was invited by a neighbour to in- 

 spect a new mode Jf heating horticultural buildings, which he termed the Pol- 

 Se system He had erected a small pit running north and south at one end 



olthic^^^ 



S&STSu* Sot * nte d P afthe e b C ott m of the chamber. Immediately 

 under the fire was the mouth of a drain, which ran to the other end ot the pit 

 and though which the cold air was drawn. I went into the pit, and found 

 there was ast earn of hot air flowing from the chamber d a very high tempe- 

 rature so hot hat it had discoloured the paint on the wood directly above. A 

 hermometer was placed at each end of the pit ; the one most distant from the 

 St Sated 71°, and the other 70°. The current passing along the top could 

 not have been le s than 90° in the centre of the pit, and nearer he chamber 

 much Wher. He proposed to modify the heat at the entrance irom , the chamber, 

 al d 1 Sen the air by hanging a wet blanket over the hole Th.s part ot his 

 XnTobectedto, for many reasons, and being about to erect a pit of similar 

 Form I Solved to get rid if the blanket, which I have as well as ot all the 

 otter' objections given in your paper, and that too at a very light expense. 

 I thnk can convince you that I have set this grand principle free, and thus 

 disencumbered it of the load of objections so unworthily heaped upon it Every 

 otTer mode of heatiug horticultural buildings will soon disappear; its cheapness 

 2S,rS fitness wfll, I am sure, throw out of use the boiler pipes tan , and 

 manure-bed I will now attempt to describe my pit; itis42teet long by » 

 fee Tid in side, high roofed, having an east and west aspect, with a wall across 

 the .middle dividing it equally. One half is used for propagating, and the other 

 for geenhoue plants. At the end of the propagating compartment, I have 

 builfa chamber 30 inches wide by 3G inches long, ami 24 inches high. In this 

 is placed riron stove, 17 inches long, 12 inches wide, and 2 inches in height; 

 abS ,2 inches of the air-chamber is carried into ^^^-fW^J 

 nart is covered with strong slates, giving a chamber ot 21 feet long by 8 iett 

 wide a ml 30 inches deep.^ Into this the hot air flows through a hole at the top 

 of the chamter, over which I have placed a piece of sheet iron, which is bent 

 downwards to" diffuse the heat and prevent its vocnce doing injury Jrom the 

 bottom of the chamber a cold-air drain is carried the whole length of the pit, tor 

 minatint: with an eye at the end of the cold compartment. On this eye a slide 

 EX to close the drain when required. In the large chamber there is another 

 eve, which is left constantly open. I have built a small flue round the large 

 chambe the smoke is conducted through the hot-air chamber into the flue and 

 back into' the chimney by iron pipes, which assist in heating this part as we 1 as 

 L giving aVaddUkmal Jraught to the chimney, as will be readily perceived by 

 the e urn-nine passing through great heat. W hen I wish to warm the part in- 

 ended fo ant ,1 can do so'in a few mmutes, by drawing a slide which covers 

 a hole that passes through the division wall into the large chamber. Th.s 



