In our illustrations, C is a knife-edge rail, upon which run grooved wheels supporting the pugging box. To the axle of one grooved wheel a connecting rod from crank arm, F is attached to effect the to-and-fro motion of the mixing box, B. G is the door of the box, B, hinged at H, and secured by hinged pins carrying fly nuts. A cover and hopper and also a trap may be supplied to the box, B, for continuously feeding and discharging the material operated upon. L, L, are the pugging blades or discs on shafts, M. The shafts, M, pass through a slot in the box, B, and the packing of these shafts is effected by the face plate sliding and bearing against the face on the standard of the machine. P is a guide piece on the standard, against which bears and slides the piece, Q, bolted on to box, B, to support and guide the box, B, in its movement. The forked ends of a yoke engage with the collars, S, on the shafts, M, this yoke being set by a screw so that the shafts may be easily removed. The machine is driven from the pulleys and shaft, T, through gearing, T2 and T3, and by the Ewart's chain on the wheel and pinion, V and U.--_The Engineer._ * * * * * [Continued from SUPPLEMENT, No. 311, page 4960.] PRACTICAL NOTES ON PLUMBING.[1] [Footnote 1: From the London _Building News_.] BY P.J. DAVIES, H.M.A.S.P., ETC. TINNING IRON PIPES, COPPER OR BRASS-WORK, BITS, ETC. Previously, I described the method of tinning the bit, etc., with resin; but before this work on joints can be considered complete, I find it necessary to speak of tinning the ends of iron pipes, etc., which have within the last fifty years been much used in conjunction with leaden pipes. This is done as follows: Take some spirits of salts (otherwise known as hydrochloric acid, muriatic acid, hydrogen chloride, HCl), in a gallipot, and put as much sheet-zinc in it as the spirit will dissolve; you have then obtained chloride of zinc (ZnCl). A little care is required when making this, as the acid is decomposed and is spread about by the discharged hydrogen, and will rust anything made of iron or steel, such as tools, etc. It also readily absorbs ammoniacal gas, so that, in fact, sal ammoniac may also be dissolved in it, or sal ammoniac dissolved in water will answer the purpose of the chloride of zinc. Having the killed spirits, as it is sometimes called, ready, file the end of your iron or bit and plunge this part into the spirits, then touch your dipped end with some fine solder, and dip it again and again into the spirits until you have a good tinned face upon your iron, etc.; next you require a spirit-brush. SPIRIT-BRUSH. You can make this by cutting a few bristles out of a broom or brush, push them into a short piece of compo tube, say 1/4 in., and hammer up the end to hold the bristles; next cut the ends of the bristles to about 3/8 in. long, and the brush is ready for use. SOLDERING IRON TO LEAD.