364 



THE GARDENER'S MONTHLY 



[December, 



that I have put in practice and found to work 

 well in my own case, but have not noticed else- 

 where, though it may not be new to others. It 

 is to use ordinary roofing slate for the bottom of 

 greenhouse flues. They can be had anywhere, 

 nine or ten inches wide by eighteen or twenty 

 inches in length, and are cheaper and better 

 than brick to use in long horizontal flues, occu- 

 pying less space ; and the slate I use only re- 

 quires to be supported twenty inches apart in- 

 stead of the eight inches that brick require. As 

 these flues are always better on, or partly buried 

 in the earth, for a short distance from' the fur- 

 nace, to modify the excess of heat by lessening 

 the radiating surface, no slates are needed so 

 close to a furnace that there is any danger of 

 their cracking by the heat when they are covered 

 with a coating of mortar in which the side bricks 

 are imbedded. From the nature of things, the 

 top of a flue is always hotter than the bottom, 

 and I have never thought it safe to try to use 

 them on top, where they are more liable to break- 

 age from other causes; but would have no hesi- 

 tation in covering the flue also at a distance of 

 forty to fifty feet from the furnace. They will 

 absorb and radiate nicely, but we know that a 

 blaze or extreme heat will cause them to fly to 

 pieces. The slates I use each have a surface 

 equal to five, and a part of them of six bricks. 

 These are supported on stone at their junctures, 

 and leave a clear space under the flue for free 

 circulation of air, and this is an additional gain. 



In choosing slate for this use, I do not pick 

 out very thin ones, but with a little care in first 

 laying the flue there is no weight to break them, 

 the brick being nearly self-supporting when 

 mortar is dry. With this foundation it is easy 

 to build these horizontal chimneys five inches 

 in inside diameter, and thus insure a good draft. 



There are special tiles made for this use, 

 but they have no advantage that I know of over 

 slate, and are not to be had every where. 



COOL ORCHIDS.— Stanhopeas. 



BY W. 



Although strictly speaking all the species of 

 this curious genus are not cool orchids, they all 

 are as well adapted to cultivation in any ordinary 

 greenhouse, as many of those which are found 

 at greater altitudes. This the writer has tho- 

 roughly tested for the past two years, and can 

 therefore speak from experience. 



With exception of the large family of Epiden- 

 drums, the Stanhopeas are of the easiest culture. 



and can be grown as successfully by the amateur 

 as a geranium or fuchsia. Notwithstanding they 

 are chiefly natives of the hottest parts of Mexico 

 and South America, they seem to have a greater 

 capacity of accommodating themselves to a 

 moderate degree of heat, I might almost say an 

 absence of it, than any members of this wonder- 

 ful family. One species is included among the 

 orchids successfully grown out of doors in 

 Bohemia during June, July and August, 1852, 

 and subsequent years, and I am convinced that 

 partially shaded, they will grow equally well 

 from May to September in the latitudes of Balti- 

 more and further South in the open air, as they 

 have done under glass without fire heat. Like 

 all orchids, except those coming from equatorial 

 regions, many of which will grow continuously, 

 they require a season of rest and growth, and 

 blossom during the summer and autumn months 

 only. Simultaneously with the flower stems, the 

 young growth appears and pushes forward 

 vigorously, many of the leaves and pseudo 

 bulbs attaining the height of two feet. During 

 this season they need a liberal supply of water, 

 and if the leaves are occasionally syringed it 

 will prevent the attacks of the red spider and 

 thrips. After their growth has been completed, 

 water should be gradually withheld, and only 

 sparingly given until the time for their flower 

 spikes to be developed in the spring. For those 

 who are commencing the culture of orchids, 

 there are none better adapted to their wants, as 

 they are easily cared for in winter, it being only 

 necessary to keep them in a light and airy posi- 

 tion where the thermometer does not fall below 

 40° at night. As a proof of the ease of their 

 culture, I will say that a plant of S. Martiana in 

 the summer of 1879, developed a spike of seven 

 flowers while suspended from the roof of a 

 greenhouse by a string, without basket, moss or 

 any attention, save an occasional syringing, and 

 also made new growth, and a plant of S. Wardii, 

 imported in July, although without foliage, is 

 now sending down a strong flower scape. They 

 should be invariably grown in baskets, open at 

 the bottom and the sides, made of small cedar 

 or locust sticks, six to eight inches in length and 

 four deep; the bottom of copper wire or sticks 

 half an inch apart, to permit the flower spikes 

 to find their way through with ease, as they 

 always take a downward direction, and are often 

 blighted if they meet with any obstruction in 

 their course; and these baskets must be sus- 

 pended from the roof near tlie light, protected 



