Both steam and hot water are extensively used in greenhouse heating. Each system has its staunch friends. It costs more money to install a hot water system, but it is more economical to operate and the pipes when kept filled with water are more permanent. With hot water, the boiler may be left for a longer period at night without attention because the pipes when filled with circulating warm water retain heat much longer than steam. Hot water, therefore, is nuch more desirable for small houses than steam because the gardener can get along without a night fireman. Whatever the system, it is important that a boiler and radiating surface of pipes be adequate to maintain the proper temperatures in the coldest weather. With a first-class hot water system, it is possible to leave the boilers for seven or eight hours even at zero temperatures outside. No greenhouse plant is complete without a good potting or transplanting room. It is often convenient to have this room over the boiler room or adjacent to it. See that it is properly heated, ventilated, lighted and well provided with good work tables or benches. This room should be made pleasant and comfortable to secure the best service of the workmen.

SASH FOR HOTBEDS AND COLD FRAMES.

In the purchase of sash, it is economy to buy the best material. Well cured cedar or cypress should be used, although white pine is considered just as durable by some who have had many years of experience in the management of frames. A prominent gardener of Philadelphia county is using quite a number of white pine sash which were bought at least twenty-five years ago and they are still in good condition. Cedar or cypress, however, are generally used.

Sash differ greatly in style of construction. A bracing rod in the middle is highly desirable, but many firms do not use it. The joints should always be leaded and the lumber smoothly dressed. The standard size is three by six feet, although larger ones are used extensively in Philadelphia county. They also vary in thickness from one and three-eights to two inches. The lighter sash are casier to handle but less durable and more likely to be lifted and broken by the wind.

In glazing sash either of these two methods is used, to butt the glass which slides in grooves, or to lap the glass which is the more popular plan. There is greater leakage when glass is butted and the sash is probably not so durable with the open grooves which collect and retain moisture. Ten by twelve inch glass is almost universally used in the three by six foot sash. Smaller lights are in common use on the larger sash, but there are serious objections to small panes. It is true, that in case of breakage, the cost of repair is less, but sash are much more tedious to glaze when the lights

are so small and the additional bars and extra laps materially reduce the amount of light that can enter the frames.

Sash should be given two coats of paint before glazing and one after. They should also be painted every other year and stored in the dry or stacked when not in use.

DOUBLE GLASS SASH.

Two firms at least are placing on the market double glass sash, and many gardeners desire information regarding their merits as compared with single glass sash. Double sash are made thicker so it is possible to provide a more or less dead air space between the two layers of glass.

The advantages are as follows: (1) Plants are afforded almost, if not altogether as thorough protection as with single glass covered with mats. It is possible, however, that single glass sash and new rye straw mats will give better protection during severe weather. In many parts of the country double sash should give all the protection needed by plants ordinarily grown in frames. (2) The labor bill in the management of frames is reduced because there are no mats to be handled morning and evening. (3) The plants receive the light during the entire day because there are no mats at any time to obstruct the light. (4) A growing temperature is reached earlier in the day and is maintained longer unless there is little or no sunshine.

The following disadvantages may be stated: (1) Double glass sash cost at least one-third more than single. (2) They are much heavier to handle but will be broken less by the wind lifting them. (3) They may not be so durable. Some growers claim that the condensation of moisture between the glass will shorten the life of the sash. It is held by some that this moisture and the accumulation of dirt between the glass reduces the amount of light entering the frames, and thus weaker plants result. There is a place in gardening for double sash, although the cheaper and lighter single form with mat protection when necessary will doubtless continue to be popular in most sections.

MAKING HOTBEDS.

In the absence of greenhouses, hotbeds are necessary to start early vegetable plants. They are heated in various ways, sometimes by flues running the length of the frames a few inches or perhaps a foot or more under the surface of the ground. Steam from farm boilers is also quite a satisfactory method when it is forced through drain or sewer tile placed a few inches below the surface of the soil in the frames. Steam or hot water may also be used, as in the heating of greenhouses, and this method is unquestionably the most