All drain pipes should be proved to be watertight by plugging up the lower end of the drain pipe and filling it with water.  In no case should a soilpipe be built inside a wall.  It should be so placed as to be always accessible. 2.  The pipes should be generally 4 in. diameter.  In no instance need a drain pipe inside a house exceed 6 in. in diameter. 3.  Every drain of a house or building should be laid with true gradients, in no case less than 1/100, but much steeper would be preferable.  When from circumstances the drain is laid at a smaller inclination, a flush tank should be provided.  They should be laid in straight lines from point to point.  At every change of direction there should be reserved a means of access to the drain. 4.  No drain should be constructed so as to pass under a dwelling house, except in particular cases when absolutely necessary.  In such cases the pipe should be of cast iron, and the length of drain laid under the house should be laid perfectly straight—­a means of access should be provided at each end; it should have a free air current passing through it from end to end, and a flush tank should be placed at the upper end. 5.  Every house drain should be arranged so as to be flushed, and kept at all times free from deposit. 6.  Every house drain should be ventilated by at least two suitable openings, one at each end, so as to afford a current of air through the drain, and no pipe or opening should be used for ventilation unless the same be carried upward without angles or horizontal lengths, and with tight joints.  The size of such pipes or openings should be fully equal to that of the drain pipe ventilated. 7.  The upper extremities of ventilating pipes should be at a distance from any windows or openings, so that there will be no danger of the escape of the foul air into the interior of the house from such pipes.  The soilpipe should terminate at its lower end in a properly ventilating disconnecting trap, so that a current of air would be constantly maintained through the pipe. 8.  No rainwater pipe and no overflow or waste pipe from any cistern or rainwater tank, or from any sink (other than a slop sink for urine), or from any bath or lavatory, should pass directly to the soilpipe; but every such pipe should be disconnected therefrom by passing through the wall to the outside of the house, and discharging with an end open to the air.  I may mention here that the drainage arrangements of this Parkes Museum in which we are assembled were very defective when the building was first taken.  Mr. Rogers Field, one of the committee, was requested to drain it properly, and it has been very successfully accomplished.

I would now draw your attention to some points of detail in the fittings for carrying away waste water.