448 



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 



