PITS AND FRAMES, 139 
These houses are also useful for early potatoes, lettuces 
and other salad plants in the winter and spring, as well as 
for cauliflowers in the autumn, and also for forcing narcissus 
and other bulbs planted directly in the ground, and for 
numerous other purposes which will quickly suggest 
themselves to the practical nurseryman or market grower. 
There are certain minor disadvantages connected with 
the system, which is doubtless only in its infancy yet, 
but these will all be surmounted in time, no doubt, and 
the principle itself is an admirable one. 
The travelling greenhouses were invented by Dr. 
Pickering, of the Horticultural Travelling Structures, Ltd., 
of White Street, Moorgate Street, London, who also 
erect them for growers, etc., on very moderate terms. 
A large number of these houses have been erected by the 
firm for several of the leading growers of tomatoes, grapes, 
cut flowers, etc., for market, at various points along the 
south coast and elsewhere, during the last few years, which 
