ORCHID-HOUSES. 



411 



the whole stage and floor can be over- 

 flowed with water at pleasure. The sunk 

 shelves are filled up with small pebbles, 

 and on these the pots are placed. A 

 Grecian fountain is placed in the centre 

 of the house, the water from which falls 

 into a basin in which aquatic plants are 

 cultivated. The waste water is conveyed 

 into a large tank holding 2000 gallons, 

 which is used for the plants, pipes, &c, 

 and is all rain water collected from the 

 roof of this and other buildings adjoin- 

 ing. The space under the stage is used 

 for forcing sea-kale, mushrooms, and 

 rhubarb, during winter. The house is 

 heated by hot-water tanks, and pipes 

 underneath them to return the water to 

 the boiler. The tanks are metal, and the 

 boiler used is one of Burbidge and 

 Healy's ribbed ones, which, Mr Lyon 

 thinks, is a decided improvement, as 

 it exposes a much larger surface to the 

 action of the fire, and thereby derives a 

 much greater benefit from the same 

 quantity of fuel than could be obtained 

 by a plain boiler. 



The orchid-house in the Belfast Botanic 

 Gardens, fig. 565, differs from the fore- 



going examples, inasmuch as it is of the 

 lean-to form, whereas all the others are 

 span-roofed. The same error has been 

 fallen into here as in other houses we 

 have noticed — namely, the carrying the 

 stone shelves in front into the parapet 

 wall, thereby preventing the ascent of 

 heat from the pipes. We observe also, 

 that Mr Ferguson, the highly respectable 

 curator, has his plants set on stone tables, 

 the centre one especially, so arranged at 

 the edges as to hold water, upon which 

 the plants are set; but they are elevated 

 a few inches above it, being set on stones 

 or otherwise raised. There are two prin- 

 cipal reasons given by cultivators for 

 adopting this practice — namely, to secure 



the plants from the attacks of wood lice, 

 cockroaches, &c, and also to give out 

 humidity to the atmosphere. Cleanli- 

 ness prevents the attacks of the former, 

 and copious syringing provides for the 

 other. Here we observe a provision made 

 for collecting the condensed steam and 

 the rain-water that finds its way through 

 the roof, by introducing copper or zinc 

 gutters to prevent its falling on the plants. 

 If the glazing be in proper repair, and the 

 necessary ventilation provided, all this is 

 unnecessary, and only gives the appear- 

 ance of imperfection and decay to the 

 structure. For a lean-to house its ar- 

 rangement is as good as can be, and the 

 plants under Mr Fergusons care are well 

 grown. We would, however, have placed 

 the upright supports perpendicularly 

 under the ridge, by adding to the main 

 table and dispensing with the back one 

 altogether. At present they do not give 

 that appearance of support which they 

 are intended to do; but, even as it is, 

 they are much better than similar sup- 

 ports we lately saw in a pine-stove erected 

 for a Scottish nobleman, where the same 

 kind of supports are nearly a foot out of the 

 perpendicular. The back part of the roof 

 is opaque, a circumstance rendered unne- 

 cessary since this house was built, as such 

 structures can now be covered with glass 

 cheaper than with boarding and slates. 



In the construction of an orchid-house, 

 a full command of heat, and means of 

 applying moisture, should be secured. In 

 regard to capacity, a medium-sized house 

 should be preferred ; for if too lofty, it is 

 difficult to keep either moisture or tem- 

 perature at their proper points, both 

 during hot dry weather in summer, and 

 severe frosts in winter, when strong fires 

 are required. Small houses have also 

 their faults, although in a less degree, as 

 they are unfit for showing to advantage 

 large specimen plants, and are liable to 

 sudden changes of temperature and mois- 

 ture, being easily acted upon by external 

 causes. The form should be span-roofed, 

 having the ends in any direction except- 

 ing due east and west, or the nearest 

 points thereto. In width it should not 

 exceed 14 or 15 feet, and presenting an 

 angle not exceeding 30°. In glazing, 

 rough plate-glass should be used, as 

 rendering artificial shading unnecessary ; 

 the laps should be closely puttied ; wide 



