This section is from the book "Commercial Gardening Vol1", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
About twenty years ago the idea of having movable greenhouses occurred to the Horticultural Travelling Structures Company, and many of their buildings are now to be seen in actual use by market growers in all parts of the kingdom. This company has protected and patented its structures, and are the only builders in the United Kingdom. Quite recently some American growers have had similar greenhouses built on the same principles. The system consists in having a rail at each side upon which the greenhouse rests and runs along by means of wheels when it is necessary to move it from one crop over another. The Plate shows how the rails are fixed at the sides and between two houses. The rail in the centre is of rolled steel channel iron, and rests on iron stanchions bedded in concrete, and serves the purpose of a gutter as well as a railway. The outside rails either rest on brickwork or on stanchions; in the latter case the spaces between the stanchions being filled in with creosoted boarding.
These travelling glasshouses are used chiefly for bulbs, Strawberries, and low-growing crops generally, and in cases where a rotation is required without the application of much heat for forcing purposes. In England where the houses are in use, three crops of bulbs - chiefly Narcissi - and one crop of Tomatoes, are generally produced during the year. In the Channel Islands, however, four crops of bulbs are often grown one after the other.
A modified type of glasshouse has recently been brought out by the same company. It is from 40 to 50 ft. wide, with high sides to the eaves to allow greater headroom for the crops. Such wide houses are common in the United States, where the roofs are trussed by rolled rods fitted together by forgings or screwed together in castings. This wide type of house is considered superior to the older forms although it is more expensive to erect. The Horticultural Travelling Structures Company have substituted substantial wires for the rods used in the American houses, and this reduces the cost considerably, and the new system, which has been patented, can be applied to houses 30 ft. wide as well as to those of wider dimensions.
The other photographs show some of the more generally adopted glasshouses used by market nurserymen in England. They are from designs made by Messrs. W. Duncan Tucker & Sons, of Tottenham, who not only erect them for the trade, but also supply timber already prepared to growers who prefer to erect their own greenhouses.
GREENHOUSES ON RAILS, SHOWING MOVABLE ENDS AND RAIL BETWEEN.
INTERIOR OF GREENHOUSE ON RAILS, SHOWING CROP OF NARCISSUS Overhead arc strings tied up to be used for crop of Tomatoes during the summer.
Photos. Horticultural Travelling Structures Co.