CONSTRUCTION AND HEATING OF GLASS HOUSES. 59 



which is held in them by capillary attraction, this being in such 

 cases with small quantities of water greater than the attraction 

 of gravitation, thus causing a much more rapid decay than would 

 occur with the use of the beveled ship siding above described, 

 besides not giving the house the longitudinal bracing and stability 

 so very desirable in such a structure. 



For the outer siding two patterns of milling are in general use ; 

 seven-eighths-inch clapboards, and novelty siding. The latter 

 makes the neater, warmer, and more durable covering. This 

 second, or outer, siding should be divided from the inner by 

 means of some non-conducting material. I think the best for this 

 purpose is a good grade of rosin-sized building paper. A grade 

 weighing about one- twelfth of a pound per square foot would be very 

 well adapted. This paper should be tacked directly to the inner 

 siding, and the outer siding should be nailed directly over this, 

 -care being taken to mismatch all joints of each of the sidings, 

 and make all vertical joints over main or intermediate posts. It is 

 a very bad practice to nail to the inner siding only, as the nails 

 will push through and present a very unsightly appearance, 

 allowing moisture to settle on the breaks thus made, and causing 

 rust and premature decay ; also not giving sufficient hold to the 

 nail, and allowing the outer siding to be drawn off if it has any 

 tendency to warp caused by the heat of the sun or by outer 

 moisture. 



The next detail to be considered is the eaves-plate or, as many 

 call it, the lower glazing strip. Its size and shape vary somewhat 

 under differing circumstances. Its main object is to afford a 

 support for the glass and glazing bars, and make a weather-tight 

 connection between the board sides and the glass roof. A very 

 convenient size and shape for this piece, in the house under 

 consideration, would be six inches by two inches, having on the 

 under side two plow grooves, the lower and larger one being for 

 the reception of the upper edge of the outer siding ; the upper 

 one, a small groove about a quarter of an inch square, to act as a 

 break, and prevent the waters of condensation from the roof 

 reaching the siding, the groove causing the water to fall at that 

 point. On the upper side, no special milling is necessary, but the 

 two edges, especially the upper one, should be cut to a slight 

 bevel. This is to give a bearing for the glazing bar. If your 

 wood is being machined in a well-appointed mill, I would also 



