Another form of gutter is that shown in Fig. 454, in which the lead is merely a lining to the gutter hollowed out in the cornice.

Such a gutter is very commonly used, especially in the North, but it is open to considerable objection. It is impossible, for want of depth, to form drips in the stone, and the lead must be in one long piece, composed of sheets soldered together, and liable to great contraction and expansion; or the joints between the sheets must be lapped, which makes the surface uneven and insecure.

Cesspools1 are small cisterns formed in lead gutters at those points where it is intended to get rid of the water.

Fig. 456 shows two such cesspools, marked cp in plan. One of these is partly seen in elevation in Fig. 476.

1 Sc. Drip Boxes.

The cesspool is a wooden box lined with sheet lead, turned up on all its sides, which are covered by aprons.

It should, if possible, be made the same size as the gutter. If not, it will be a source of trouble, and difficult to make watertight.

In the illustration given in Fig. 476 a channel is cut through the coping connecting the cesspit with the head of the down pipe. The mouth of this communication is protected by a perforated zinc rose or grating, to prevent dead leaves or rubbish from getting into and choking the down pipe.

Iron Gutters are cast by the founder, but the work of arranging them generally devolves upon the plumber.

Eaves Gutters l run along the lower edges of the roof slopes, and are fixed in different ways.

Fig. 3 19 shows semicircular gutters1 resting on holdfasts nailed to the boarding of the roof. The ogee gutter in Fig. 325 is secured at intervals to the fascia board. The moulded gutter in Fig. 372 rests upon the wall, and that in Fig. 365 on a projecting sailing course or upon corbels. •

Both these positions should be avoided if possible, for where the gutter rests upon the wall it will be constantly leaking into it, causing damp, and injuring the masonry.

Iron Valley Gutters are often used, and may be obtained either of sections like V gutters gradually varying in depth and width throughout their length, or of uniform cross section throughout like trough gutters.

The V gutters must of course be cast to suit the pitch of the roof, or the pitch arranged to suit such patterns as may be kept in stock.

Fig. 363 shows a cast-iron trough gutter at the back of a parapet wall.

Zinc Gutters for eaves may be semicircular or moulded, and fixed in the same way as iron gutters; but zinc valley or trough gutters are laid somewhat in the same way as those of lead.

Rain "Water Pipes.2 - It has already been mentioned that all gutters should lead to vertical down pipes, which conduct the water to drains provided to carry it off.

These pipes are generally of cast iron, circular in section, and about 3 or 4 inches diameter, the size varying according to the amount of water they will have to carry off.

1 Sc. Ehones or Runs.

2 Also called "Down-comers," "Stack Pipes," "Spouting," and "Rain "Water Pipes." Sc. Conductors, Wall Pipes.

They are secured by spikes driven into the wall through ears cast on each length of pipe, or by collars with ears spiked to the wall, or by patent methods which cannot be described here.

Zinc pipes, and even lead pipes, are similarly used, but they are not common, and need not further be noticed.

The openings into heads of all down pipes should be protected by a rose similar to that shown in Fig. 476, to prevent dirt and rubbish from getting in and choking the pipe.