STO 



852] 



STO 



its farther extension in length. It is 

 frequently done, either to promote its 

 robustness, or to promote the produc- 

 tion of laterals. 



STORAX. Sty' rax. 



STORK'S BILL. Pelargo'nium. 



STOVES, or Hothouses, are glazed 

 structures, differing from greenhouses 

 chiefly in requiring a higher tempera- 

 ture to he sustained within them, either 

 for forcing fruits or for growing plants 

 from tropical climates. Nearly all that 

 is stated relative to the greenhouse, hot- 

 bed, pit, under the article Melon, and 

 JRendle's Tank System, is applicable to 

 the stove. In addition, relative to glaz- 

 ing, if lapping be permitted, 

 its width should not exceed 

 one - eighth - of-au -inch, and 

 the panes should he acutely 

 rhomboid, to throw the con- 

 densed vapour down to the 

 lower corner, and induce it 

 to trickle down the bars in- 

 stead of dropping. It is 

 very doubtful whether it re- 

 duces the amount of mois- 

 ture taken between the laps 

 by capillary attraction. 



Flues are best built of bricks set on 

 their edges, and the top 

 formed of a shallow iron 

 trough for the purpose of 

 holding water, and thus 

 keeping the air moist as 

 required. At night, for re- 

 taining heat, pantiles may 

 be placed along within the 

 ti'ough ; the best form is 

 the annexed. 



Hot water in a tank is superior to 

 the same source of heat in pipes, be- 

 cause it is not liable to freeze ; and it 

 is preferable to steam, because its heat- 

 ing power continues until the whole 

 mass of water is cooled down to the 

 temperature of the house, whereas 

 steam ceases to be generated as a 

 source of heat, the moment the tempe- 

 rature falls below 212. If steam be 

 employed, Mr. Tredgold lias given the 

 following rules for calculating the sur- 

 face of pipe, the size of the boiler, the 

 quantity of fuel, and the quantity of 

 ventilation, required for a house thirty 

 feet long, and twelve feet wide, with the 



glass roof eight feet, length of the 

 rafters fourteen feet, and height of the 

 back wall fifteen feet. The surface of 

 glass in this house will be seven hun- 

 dred and twenty feet superficial, viz., 

 five hundred and forty feet in the front 

 and roof, and one hundred and eighty 

 feet in the ends. Now, half the verti- 

 cal height, seven feet six inches, mul- 

 tiplied by the length in feet, and added 

 to one-and-a-half times the area of glass 

 in feet, is equal to the cubic feet of air 

 to be warmed in each minute when 

 there are no double doors. 



That is, 7 ."> x 30 + 1 X 720 *= 1:105 

 cubic feet. But in a house with wooden 

 bars and rafters, about one-tenth of 

 this space will be occupied with wood- 

 work, which is so slow a conductor of 

 heat, that it will not suffer a sensiblo 

 quantity to escape, therefore 130 feet 

 may be deducted, leaving the quantity 

 to be warmed per minute --11 7<*> cubic 

 feet. 



To ascertain the surface of pipe re- 

 quired to warm any given quantity of 

 air, multiply the cubic feet of air to be 

 heated per minute, by the difference 

 between the temperature the house is 

 to be kept at, and that of the external 

 air in degrees of Fahrenheit's thermo- 

 meter, and divide the product by 2.1, 

 the difference between 200, which is 

 the temperature of the steam pipes, 

 and the temperature of the house ; the 

 quotient will be the surface of cast iron 

 pipe required. 



Now in the house, the dimensions 

 of which are above given, if the lowest 

 temperature in the night be fixed at. 

 oO, and 10 are allowed for windi, and 

 the external air is supposed to T>e at 

 zero or of Fahrenheit, then 1175 

 multiplied by 00 and the product di- 

 vided by 2.1, the difference between 

 200 and 00, will give us the quotient 

 236 to the surface of pipe required. 

 Now the house being thirty feet long, 

 five pipes of that length, and five inches 

 in diameter, will be about the proper 

 quantity. 



If hot water be employed instead of 

 steam, the following proportions and 

 information, obtained from Mr. Eendle, 

 may be adopted confidently as guides. 

 In a span-roof propagating-house, forty 



