lo July. 1911- j Silo Construction. 495 



put two 24-ft. studs opposite one another and attach to foundation posts. 

 Place the four other 24-ft. studs at third stud position each side of these 

 two. 



The next operation is the putting on of the single hoops. The.se are 

 alternately on the outside and inside of the studs, the inside hoops taking 

 the horizontal lap of the sheets of iron forming the lining and falling 

 into the checks made as already described. Mark the outside hoops for 

 pjositions of studs before putting up, by bending them round on top of the 

 upper treble hoop and against the outer faces of the studs. The hoops 

 should be fixed to the same studs as marked. This need not be done for 

 each hoop ; every second one wall be sufficient. I'nless this is done care- 

 fully, the silo will most likely have different diameters at different points 

 and trouble will ensue when putting on the lining. The outside hoops 

 should lap over so as to cross two adjacent studs. They are secured at 

 each stud with 2|-in. x |-in. bolts and at laps with 3-in. x |-in. at first 

 stud of the lap and 35-in. x |-in. at the last one. there being a plate 

 washer 5-in. x i-in. x 5 i6-in., with 7-16-in. hole in centre at the end bolt. 

 The inside hoops are fastened to the studs with two 2 -in. nails to each 

 stud. Care should be taken not to have the joints vertically above one 

 another. Nail short pieces of 6-in. x |-in. for the wddth of two studs next 

 the port hole and opposite to the inner hoops ; these will serve as a ladder 

 for access to the top and the port holes. 



Lining. — 6 ft. x 3 ft. galvanized flat iron (24 gauge) is u.sed. If the 

 studs and hoops have been erected as described, the sheets will have a lap 

 of 3 in. vertically on the studs and i in. horizontally on the hoops. Carefully 

 press the sheets out to the line of the circle before nailing, and start at the 

 centre studs, working out to the side studs. This will make the iron set 

 better. Tack with ij-in. clout tacks on the studs. 3 in. apart at the laps 

 and 6 in. at the other studs. Tack with f-in. clouts (tw'O between each 

 stud) to hoops at horizontal laps, putting clouts ^ in. up and down alter- 

 nately to avoid splitting hoop. The upper sheet in each lap is put outside 

 the lower to keep the weather out and prevent rain working in. Conse- 

 quently, this work must be started from the top of silo. Drive two tacks in 

 the hoop below the sheet at its ends to rest the iron on while tacking. 

 These tacks to be drawn when sheet is fixed. 



Roof. — Fix two purlins ior ridge 20 ft. long to the centre 24-ft. 

 roof studs, the top of studs being checked t in. on each side for 

 purlins, and purlins bolted to studs with 6i^-in. x |-in. bolts, one to each 

 stud. These jnirlins to project in order to attach block and tackle. 

 Secure in a similar manner, with 5^-in. x g-in. bolts, purlins to the third 

 stud.' each side of ridge studs, which are 24 ft. high as directed, and 

 bottom purlins to ordinary length studs — the sixth on each side of ridge 

 studs. The centre purlins are fixed to suit the pitch given by the ridge 

 studs and the excess length cut off. Cover with 9-ft. sheets of 26-gauge 

 corrugated galvanized iron, allowing a lap of one and a half corrugations, 

 with 2^-in. springhead nails at every ihird corrugation. Fix three lengths 

 of 14-in. galvanized ridging witK springhead nails every 2 feet. Fix 

 four 3-in. X I -in. hardwood battens frfim studs to ends of bottom jiurlins 

 for supports. 



Port Hole.s. — Port holes arc niadr in every alternate row of 

 iron, the sill of tlie first being pr.-lcrablv at the top of the first inside 

 h(x>i). The sills are made of 6-in. x i-in. hardwood, as .shown in the 

 dr.iwing, fixed to the top of an inside hoop and supported on two short 

 pieces of 4-in. x 2-in. skew-nailed on to outer face of studs. The sides 

 are formed of 4-in. x 2-in. pieces i)lanted on studs, notched for ends 



