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. 248. This is the _bed_ for the ice to lie on; and as you see, the top of the bed will be seventeen inches from the ground. The pressure of the ice may, perhaps, bring it to fourteen, or to thirteen. Upon this bed the ice is put, broken and pummelled, and beaten down together in the usual manner.