DREER'S VEGETABLES UNDER GLASS. 55 
They are set eight inches apart each way, and there is 
nothing especially noteworthy about their life in the forcing 
house. They are well ventilated, freely watered on bright 
days, and kept at a steady temperature. 
After the lettuce begins to head the temperature is kept 
down to 4o° at night. In day time the temperature runs up 
to 60°, but plenty of air is given. 
Some New England growers now sow lettuce seed as 
early as August 1. This puts plants in the forcing house 
about the middle of September, and yields a crop ready for 
market about November 1. 
The next crop of lettuce is treated in the same way, 
except that a two-inch coat of manure (instead of three) is 
dug into the bed. The young plants are taken from an 
in-doors seed bed. ‘The plants are, however, started in the 
same manner and are as carefully transplanted and as well 
rooted, so that no delay will follow their transfer to the forc- 
house. They are so well developed that they can be headed 
in about six or seven weeks in the large house. 
The usual routine of work is to follow two crops of 
lettuce with a crop of cucumbers (see chapter on cucumbers); 
but there is a tendency now (1896) shown toward securing 
three crops of lettuce, to be followed by cucumbers a little 
later in the spring than under the ordinary way. 
The details of the work done by the New England 
‘‘ market farmers’’ are instructive. ‘Take, for instance, their 
method of preparing manure for their forcing houses. This 
manure is hauled fresh from the city stables. The long 
straw is first shaken out. The manure is then brought to a 
uniform condition of wetness, and is rotted by repeated 
turnings. A fresh fermentation is started each time it is 
turned, until finally it is short, sweet and exactly suited for 
quick conversion into plant food. 
There is not a detail in the whole operation of lettuce 
growing in Boston that cannot be precisely duplicated in other 
