Glasshouse Building 225 



the cuts in the sides of the trough, will cut every bar exactly alike. The 

 short bars where the ventilators come have only the lower end cut like 

 this; the upper end is cut to fit the seating. 



After all the wood is cut it should be gone over and all the knots 

 and resinous places be painted with patent knotting, then a good coat 

 of priming should be given. As soon as dry, the second coat is given, 

 special attention being given to the joints. The lower side of the plate 

 should be tarred, but even if the remainder of the plate is ultimately to 

 be tarred it should be left for a year till thoroughly seasoned: for un- 

 seasoned wood, tarred, will develop dry rot very quickly. 



The end rafters are cut in the same trough as the sash bars, and care 

 must be taken to cut them in pairs, as they only have a glass rabbet on 

 one top edge for the roof, and one bottom edge for the ends. The best 

 way to avoid mistakes is to set them up in pairs and mark their top ends. 



In putting up the roof a start is made by putting up two end rafters, 

 nailing them lightly at the bottom, and leaning the ends together. 

 Holes should be bored previously for all the nails in the bars and joints, 

 to avoid splitting the wood. Two trestles tall enough for the builder to 

 reach the tops of the bars with ease will be required; a strong plank along 

 the tops will enable the builder to put up several bars without shifting. 

 A piece of ridge is now lifted up and pushed between the top ends of the 

 end rafters and held there while an assistant supports the other end of 

 the ridge with -a couple of sash bars put in position and lightly nailed 

 in place. The end rafters are now carefully adjusted and nailed fast. 

 A long piece of wood is then put up and nailed to a peg driven into the 

 ground in front of the end of the house: the other end of this piece is 

 nailed to the side of the ridge as soon as the end bars have been got 

 quite square with the plate. When this strut is fixed the roof will remain 

 firm while some more bars are put up, or till the rest of the roof is 

 finished. Two gauges, exactly the width of the glass to be used, are 

 made out of scroll iron or hard wood, and as each bar is put up these 

 gauges are put in where the glass will lie to keep the bars the right 

 distance apart while the nails are being driven. Where the ventilators 

 come a long gauge will be required, as two bars are left out till the 

 ventilator seating is in place. These long gauges want making very 

 carefully or trouble will be met with when the short bars go in. When 

 the end of the first piece of ridge is reached the supporting bars are 

 knocked away and a fresh piece of ridge is put up. The assistant holds 

 up the free end while the builder nails the other to the first piece, and 

 then gets down and supports the free end with two bars as before. The 

 purlin is fixed by boring holes right through the sash bars and the purlin 

 and driving a long wire nail right through and clinching on the inside. 

 While the roof is being built it is as well to nail long boards right across 

 the house, from plate to plate, to prevent any strain being thrown on the 

 plate before the purlin is on and properly tied and supported. 



I see that the setting of the plate has been omitted. This is put 



VOL I. 15 



