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HENDERSON'S HANDBOOK OF PLANTS 



HEA 



to twenty-four inches from the bars. The flue 

 •will always "draw " better if slightly on the 

 ascent throughout its entire length ; it should 

 be elevated in all cases from the ground, on 

 flags or bricks, so that its heat may be given 

 out on all sides. The inside measure of the 

 brick flue should not be less than 8x14 inches; 

 if tiles can be conveniently procured, thej- are 

 best to cover with ; but, if not, the top of the 

 flue may be contracted to six inches, and 

 covered with bricks. After the flue has been 

 built of brick to twentj'-ftve or thirty feet from 

 the furnace, cement or vitrified drain-pipe, 

 seven, eight, or nine inches in diameter, 

 should be used, as they are not only cheaper, 

 but radiate the heat quicker than the bricks ; 

 they are also much easier constructed and 

 cleaned. Care should be taken that no wood- 

 work is in contact with the flue at any place. 

 AVe have known cases where wood-work has 

 caught fire after the house had been in opera- 

 tion for years; but an unusually strong draft 

 intensified the heat, and the charred timber 

 ignited and totally destroyed the green-house 

 and its contents. It should be taken as a safe 

 rule, that wood-work should in no case be 

 nearer the flue or furnace than eight inches. 

 In constructing do not be influenced bj' what 

 the mechanics will tell you, as few of them 

 have any experience in such matters, and are 

 not able to judge of the dangers resulting 

 from wood-work being in close contact with 

 heated bricks. The position in which the flue 

 is placed in the green-house depends upon its 

 size. Presuming that the green-house to be 

 heated is an equal span of twenty feet wide by 

 fifty feet long, the best way is to start the 

 furnace at the north end, so that the flues will 

 run under the center or middle bench, the 

 top of the furnace being inside the green- 

 bouse, the fire, of course, being applied in the 

 shed outside. A comparatively new plan of 

 constructing flues is to have the flue run to 

 the end of the green-house, and, returning, 

 connect with the chimney, which is placed on 

 the top of the arch of the furnace. By this 

 method, as soon as a fire is lighted in the 

 furnace, the brick-work forming the arch gets 

 heated, and at once starts an upward draft, 

 which puts the smoke fiue into immediate 

 action and maintains it ; hence there is never 

 any trouble about the draft, as in ordinarj- 

 flues, having the chimney at the most distant 

 point fi'om the furnace. It will be seen that 

 by this plan we not only get rid of the violent 

 heat given out by the furnace, but at the same 

 time it insures a complete draft, and the 

 heated air from the furnace is so rapidly 

 carried through the entire length of the flue, 

 that it is nearly as hot when it enters the 

 chimney as when it left the furnace. This 

 perfect draft also does away with all danger 

 of the escape of gas from the flues into the 

 green-house, which often happens when the 

 draft is not active. Formerly the flues used 

 to be run along one side or end of the green- 

 house, emptying into a chimnej' placed there; 

 but this method is rarely satisfactory, as the 

 cold outside air, rushing down the chimney, 

 throws back the heated air, particularly in 

 high winds, so as to nearly destroy the heat ; 

 but by the method of constructing the chim- 

 ney on the top of the arch of the furnace, and 

 returning the flue back into it, no such diffi- 

 culty can occur. 



HEA 



Heating by Hot-Beds. The preparation of the 

 heating material for the hot-bed is a matter 

 of importance. It should be manure fresh 

 from the horse-stable, and when they can be 

 procured, it is better to mis it with about an 

 equal bulk of leaves from the woods, or refuse 

 hops. If the weather is very cold, the bulk 

 of manure must be of good size, from five tt. 

 six wagon loads, thrown into a compact rouni 

 heap, else the mass may be so chilled tha 

 heat will not generate. If a shed is con 

 venient, the manure may be placed there, 

 especially if the quantity is small, to be pra 

 tected from cold until the heat begins to rise. 

 The heap should be turned and well broken 

 up before being used for the hot-beds, so that 

 the rank steam may escape, and the manure 

 become of the proper " sweetened " condition. 

 It is economy of the heating material to use 

 a pit for the hot-bed. This should he made 

 from two to three feet deep, six feet wide, 

 and of any required length. After the heat- 

 ing material has been packed in the pit to the 

 depth of from twenty to twenty-four inches, 

 according to the purpose for which it is 

 wanted, or the season of the year (the earlier 

 in the season the deeper it is needed), the 

 sashes should be placed on the frame, and 

 kept close until the heat generates in the 

 hot-bed, which will usually take twenty-four 

 hours. Now plunge a thermometer into the 

 manure, and if all is right it will indicate 

 100*^ or more ; but this is yet too hot as bot- 

 tom heat for the growth of seeds or plants, 

 and a few days of delay must be allowed until 

 the thermometer indicates a falling of eight 

 or ten degrees, when the soil may be placed 

 upon the manure, and the seeds sown or 

 plants set out in the hot-bed. Amateurs are 

 apt to be impatient in the matter of hot-beds, 

 and often lose their first crop by sowing or 

 planting before the first violent heat has sub- 

 sided. Another very common mistake is in 

 beginning too early in the season. In the 

 latitude of New York nothing is gained by 

 beginning before the first week in March, and 

 the result will be very nearly as good if not 

 begun until a month later. There are two or 

 three important matters to bear in mind in 

 the use of hot-beds. It is indispensaVjle for 

 safety to cover the glass at night with shut- 

 ters or mats until all danger of frost is over ; 

 for it must be remembered that the contents 

 of a hot-bed are always tender, from being 

 forced so rapidly by the heat below, and that 

 the slightest frost will kill them. Again, 

 there is danger of overheating in the daytime 

 by a neglect to ventilate when the sun is 

 shining. As a general rule, it will be safe in 

 all the average days of March, April and May, 

 to have the sash of the hot-bed tilted up 

 from an inch to three inches at the back 

 from 9 A. M. to 4 P. M. Much will, of course, 

 depend upon the activity of the heating ma- 

 terial in the hot-bed, the warmth of the 

 weather, and the character of the plants in 

 the bed, so that we can only give a loose gen- 

 eral rule. Numbers of inexperienced amateur 

 cultivators often lose the entire contents of 

 the hot-bed by having omitted to ventilate 

 their hot-bed, and on their return home from 

 business at night find all the contents 

 scorched up. Or the danger of the other ex- 

 treme is, that the plants are frozen through 

 neglect to cover them at night. A hot-bed 



