[Illustration: _Fig. 1_, _Fig. 2_, _Fig. 3_]
245. Next come the _rafters_, as from _s_ to _n_, FIG. 2. Carpenters best know what is the _number_ and what the _size_ of the rafters; but from _s_ to _m_ there need be only about half as many as from _m_ to _n_. However, carpenters know all about this. It is their every-day work. The roof is forty-five _degrees pitch_, as the carpenters call it. If it were even _sharper_, it would be none the worse. There will be about _thirty_ ends of rafters to lodge on the plate, as at _m_; and these cannot _all_ be fastened to the top of the centre-post rising up from _a_; but carpenters know how to manage this matter, so as to make all strong and safe. The _plate_ which goes along on the tops of the row of posts, _b b b_, must, of course, be put on in a somewhat sloping form; otherwise there would be a sort of _hip_ formed by the rafters. However, the thatch is to be so deep, that this may not be of much consequence. Before the thatching begins, there are _laths_ to put upon the rafters. Thatchers know all about this, and all that you have to do is, to take care that the thatcher _tie the straw on well_. The best way, in a case of such deep thatch, is to have _a strong man to tie for the thatcher_.
246. The roof is now _raftered_, and it is to receive a thatch of _clean_, _sound_, and well-prepared wheat or rye straw, four _feet thick_, as at _h h_ in FIG. 2.
247. The house having now got _walls_ and _roof_, the next thing is to make the _bed_ to receive the ice. This bed is the area of the circle of which _a_ is the centre. You begin by laying on the ground _round logs_, eight inches through, or thereabouts, and placing them across the area, leaving spaces between them of about a foot. Then, _crossways on them_, poles about four inches through, placed at six inches apart. Then, _crossways on them_, other poles, about two inches through, placed at three inches apart. Then, _crossways on them_, rods as thick as your finger, placed at an inch apart. Then upon these, small, clean, dry, last-winter-cut _twigs_, to the thickness of about two inches; or, instead of these twigs, good, clean, strong _heath_, free from grass and moss, and from rubbish of all sorts.