ONE HUNDRED THOUSAND FACTS FOR THE PEOPLE. 425 



•does not wash off, or easily rub off, and it 

 looks well, while it will go far to preserve 

 the wood. It is, therefore, especially 

 adapted to the outside of buildings that 

 are exposed to the weather. Three coats 

 are needed on brick and two on wood. 

 If you want to get a fine cream color, 

 .add three pounds of yellow ochre to the 

 above. If you prefer a brown color, add 

 four pounds of umber, one pound of In- 

 dian red, and one pound of lampblack. 

 If you want a gray or stone color, add 

 four pounds of raw umber and two 

 pounds of lampblack. This will be more 

 dura ble th an common whitewash. 



PAINTING.— The value of paints pre- 

 pared from oxides of iron is very generally 

 overlooked by architects. These paints 

 :some men of experience pronounce to be 

 superior to those prepared from the 

 oxides of lead; at any rate, they answer 

 equally well, and the cost is considerably 

 less. But we propose to allude to the 

 value of these paints, especially for use 

 upon iron. It has been acknowledged for 

 years that the oxides of lead, or copper, 

 if put upon iron, will eat into it, and pro- 

 mote corrosion, and yet how frequently 

 do we meet with the requirement that 

 iron work shall have a coat of red-lead 

 before leaving the foundry: a worse pro- 

 vision could hardly be made, unless it be 

 to specify verdigris, a preparation from 

 •copper; this also is sometimes used, 

 though it eats holes into the iron in a 

 very short time. Very shortly after iron- 

 work is painted, the iron will be observed 

 corroded, and the remark be upon every 

 body's tongue, "This ought not to be 

 going so soon; ought not to want painting 

 so soon," The fact is, lead has been put 

 upon it, and nothing else could be ex- 

 pected. The reason red or white lead 

 causes metal to corrode so quickly is ex- 

 plained thus: directly the air gets to the 

 metal, not only does natural corrosion 

 take place, but a chemical action sets in 

 between the lead and the iron, and in- 

 creases the corrosion. No harm can re- 

 sult from painting iron with red or white 

 lead, so long as the oxygen of the air, or 

 water, does not get to the metal; but as 

 it is almost sure to do so, it is best not to 

 run the risk. The same quantity of paint, 

 made from the oxide of iron, will cover a 

 surface of twice the area as that of paint 

 prepared from lead, though the price is 



much less. Aqua fortis, one of the 

 strongest acids, if poured upon red or 

 white lead, will fuse it instantly, but has 

 no effect upon paint prepared from the 

 oxide of iron. With regard to the numer- 

 ous anti-corrosive paints in existence, we 

 may say, in one word, it is of no use try- 

 ing to cheat nature; anti-corrosive paints 

 will not answer the purpose their names 

 imply: all paints must yield eventually to 

 the action of the oxygen, and the work be 

 repainted, and for many reasons it is well 

 that all work should be repainted at 

 proper intervals. All that can be done 

 to attain the objects of such paints is to 

 to pick and form the stuff as to reduce 

 the power of the elements to affect it to a 

 minimum. This is found best secured 

 when the composition forming the paint 

 is granular, not so finely powdered as 

 ordinarily. The finer the powder of the 

 mixture, the greater the tendency for air- 

 holes to form, as the paint is being laid 

 on; paint that is more gritty, or granular, 

 affords a better opportunity for the air to 

 escape, and therefore reduces the liabili- 

 ty of corrosion to the utmost limit. The 

 coating of oil is the best preservative, 

 and not the paint mixtures; and there- 

 fore those mixtures which, like lamp-black, 

 go a long way in mixing with oil, answer 

 better than those that require more of the 

 mixture to form the paint. For covering 

 urinals or other work exposed to the in- 

 fluence of strong acid, black varnish is 

 the best article to use; it should be fre- 

 quently applied, and is inexpensive. 

 Woodwork before painting ought to be 

 well soaked with good priming, principal- 

 ly turpentine; this keeps damp out of the 

 wood; a coat of paint has not the same 

 power, as it forms a skin on the wood, 

 instead of soaking into it. The priming 

 should pass over all the woodwork, where 

 exposed; otherwise damp may come into 

 contact with the portion not primed, and 

 it will find its way down the wood, and 

 cause blisters in the paint, where we have 

 thought them unlikely ; blistering is often 

 a result of insufficient priming. Painters, 

 as a rule, neglect to prime the tops of out- 

 side doors; damp gets down the wood, 

 and blistering results. Knots will some- 

 times show through paint-work, and lead 

 to the inference that no knotting has 

 been used, whereas the effect may be 

 merely the result of using inferior stuff. 



