Page:Popular Science Monthly Volume 92.djvu/464

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��Popular Science Monthly

��can be heated either with fermenting manure, a stove, a brick flue, or by means of radiating pipes, supplied with steam or hot water from a dwelling or other heating

���■^ Cross section of a hotbed having a lower chamber heated by steam pipes

plant. For a permanent hotbed in which fermenting manure is to supply the heat, a pit 24 to 30 in. in depth should be pro- vided. The sides and ends of the pit may be supported by brick walls or by a lining of 2-in. plank held in place by stakes.

Standard hotbed sash are 3 ft. by 6 ft. in size, and are usually constructed of white pine or cypress. As a rule, hotbed sash can be purchased cheaper than they can be made locally, and they are on sale by seedmen and dealers in garden sup- plies. In the colder parts of the country, in addition to the glazed sash, either board shutters, straw mats, burlap, or old carpet will be required as a covering during cold nights. It is also desirable to have a supply of straw on hand to throw over

��that the bed may become sufficiently warm before nightfall.

Hotbeds should be watered on bright days, and in the morning only. Water- ing in the evening or on cloudy days will have a tendency to chill the bed and to increase the danger from freezing. After watering, the bed should be well ventil- ated to dry the foliage of the plants and the surface of the soil, to prevent damage to the plants from damping-off fungus or mildew.

The construction of a cold frame is the same as that of temporary hotbeds, ex- cept that no manure or other heating material is provided. Cold frames are covered by means of ordinary hotbed sash, or cotton cloth may be substituted for the sash. In the North, the use of the cold frame is for hardening plants that have been started in the hotbed, preparatory to setting them in the garden. In the South, where the weather is not so severe, the cold frame is made to take the place of the hotbed in starting early plants. The same methods of handling recommended for a hotbed should apply to a cold frame. Thorough ventilation should always be maintained in any style of hotbed.

���A cross section of a hotbed with an enlarged pit for the heating material

the bed in case of extremely cold weather. During bright days, the hotbed will heat very quickly from the sunshine on the glass and it will be necessary to ven- tilate it during the early morning by slightly raising the sash on the side away from the wind. Care should be taken, in ventilating, to protect the plants from a draft of cold air. Toward even- ing, the sash should be closed in order

��Properly Lubricating Automobile Spring Bolts

WHERE hard oil is used as a lubricant for automobile spring bolts, it sometimes dries in the small holes and grooves that feed it to the bearing surfaces, thus preventing the parts from being prop- erly lubricated. This causes the bolts and spring eyes to wear out quickly. A way is illustrated where- by this condition may be remedied successfully by adopting oil cups for thin oil.

Drill a hole large enough to allow the oil to be poured in through the cap and threaded portion of the bolt as shown in the illustration. Then turn the cap half way around, thus com- pletely closing the hole.— Ouis REYNOLDS.

���Using thin oil in hard grease cups

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