The figure 178 (wet method alone) is probably much too high, because, while it is true that pumicestone and water alone are used for the flat surfaces of the body--the bulk of the work--dry sandpapering of the first two priming coats and of the final finishing coats (when of white, cream, or yellow colour), of the under parts of carriages, iron chassis of motor-cars, and of curved surfaces, such as the spokes of wheels, is almost universal. The reason for thus treating the priming coat dry is that a wet process would raise the grain of the wood. The 52 factories in which it was stated that no smoothing was done were nearly all premises for the repair or manufacture of railway trucks, requiring no special finish, and the 39 factories in which only sandpaper was said to be used in smoothing were premises in which rough, cheap, or common vehicles, such as carts, were made. Use of sandpaper is quicker and less expensive than use of pumicestone, and water and wet methods cannot be used very well on iron surfaces. In ordinary coach and carriage painting, after the sandpapering of the first two priming coats, six or seven coats of “filling” (usually ground slate mixed with gold size and turpentine) are applied, and each coat is rubbed down wet. Joints and interstices of woodwork and irregularities in iron surfaces are generally filled in with a stopping or paste of white lead, in the smoothing of which sandpaper is used. In the manufacture of motor-cars, the terne (lead) coated sheets which form the body, after preliminary preparation, receive two coats of a lead paint. These are either lightly sandpapered or “flatted” with pumice and water. Three coats of non-poisonous filling follow, and are flatted with pumice or German brick and water. The body then passes to a skilled workman, who applies the final coats of colour. For facing mouldings and for corners throughout all stages of the processes, dry sandpaper takes the place of pumice and water. All stopping on the chassis, the first lead coat on the bonnet, and all coats of paint on the wheels, are sandpapered dry. Sometimes a third of a man’s time may be taken up in sandpapering alone. _Dangers and Prevention._--Grave risk of inhaling lead dust is present (see the table on p. 47) when sandpaper is used, often at a point just above the mouth and nostrils. Rubbing down the wheels is perhaps the most dangerous work, and for this exhaust ventilation can be applied locally. Inventive genius has yet to be directed to some modification of the vacuum-cleaning apparatus, so that an exhaust can be attached to the back of the worker’s hand or in connection with a frame in which the sandpaper is held. In the process of wet rubbing, the abraded coats drip on to the floor, and when dry may rise as dust into the atmosphere.