If possible, both latches and handler-pits should be provided with plugs and underground pipes, communicating with a liquor-well some feet below their levels. Glazed fire-clay is very suitable both for pipes and plug-holes, which should be in the pit corners. Some means should also be provided for the ready clearing of the pipes when choked with tanning materials. A good plan is to let each line of pipes end in a liquor-well large enough for a man to go down. As it is almost impossible to make plugs fit without occasional leakage, it is not well to run pits with very different strengths of liquors to one well, but the layers, handlers, and different sets of leaches should each have their own, so as to avoid mixture. A good means of clearing pipes consists in a series of iron rods 3-4 ft. long, connected by hooks fitting into double eyes, as shown in Fig. 63. It is obvious that in a narrow pipe or drain, these cannot become disconnected. [Illustration: Fig. 63.] It is, as Schultz points out, of questionable advantage to lay wooden troughs for supplying liquor to each pit under the alleys, since it is almost impossible to preserve them from decay; but the same objection would not apply to glazed pipes, well clayed or cemented. A very good and cheap plan in practice, is to let the liquor-pump, or a raised liquor-cistern, discharge into a large and quite horizontal trough raised 5 or 6 feet above the level of the yard, and provided with plug-holes at intervals, under which short troughs may be set to run the liquor into the various pits. [Illustration: PL. VIII. _E. & F. N. Spon, London & New York._ "INK-PHOTO." SPRAGUE & CO. LONDON. RUBBING-DOWN DYED SKINS.] In tan-yard construction, iron should, as far as possible, be avoided wherever it can come into contact with liquor, as it discolours the leather. In default of underground pipes, india-rubber suction hose may be employed. Direct-acting steam pumps without fly-wheels are not suitable for tanneries, as they "hammer" when the pit is nearly sucked up. Steam-jet elevators and the pulsometer are very useful for some purposes, but slightly warm, and dilute the liquors with condensed steam. [Illustration: Fig. 64.]