扁平木箱。

扁平木箱。

Considering the many failures of flat-hoop wooden roof-tanks and not least on the roofs of buildings equipped with automatic sprinklers, the advice against them as recently offered by the New York Fire Insurance Exchange to the owners and occupants of such buildings to substitute round for flat-hoops is timely. Referring to the collapse of a tank on the roof of Adams’ department store on Sixth avenue, Manhattan, which was due to the corrosion of the flat (band-iron) hoops, the writer points out that the “most frequent cause of tank collapse is corrosion of the hoops, whereby their strength is so reduced as to lead finally to rupture. The ordinary hoop is a flat iron band, ⅛-in. to 1/4-in. thick and of varying widths. It is seldom painted either before or after being put on; and, exposed, as it is, to the weather, as well as to the acids generated in the wood, corrosion is rapid, because moisture works into and through the staves and attacks the inner side of the hoop even more than the outer, so that, while the outside corrosion is easily observed,' the inside is out of sight, and the real condition of the hoops is often not known until a collapse occurs. As a matter of fact, hoops have been found, either through examination or through their breaking, that were hardly thicker than a Sheet of paper, the corrosion having taken effect chiefly on the inner side. Such hoops may look to be in very fair condition, so far as can be determined from the outside; but the only way to arrive properly at their condition is to reinforce the tank with additional round iron hoops and then remove the flat ones for examination. It is fair to assume that ¾1 flat hoops which have been in place for any. length of time are corroded, and their, strength' more or less impaired; and it would seem to be the only prudent course to replace all such hoops with new, round iron hoops, which insurance engineers have agreed are safer and less likely to give way than flat or band iron. A round iron hoop has these advantages: Corrosion from the inner side acts only on a small surface as compared with the flat band, and ordinary inspection should disclose , such corrosion before it had progressed sufficiently to weaken the hoop; practically, the entire hoop can be frequently painted so as to prevent corrosion; swelling of tank is less likely to burst the hoop, as the round iron will indent itself into the wood. These hoops should be of wrought iron or mild steel, without welds, thoroughly painted before, and kept so after the erection of the tank. No round iron less than ¼-in. in diameter should be used and spacing between hoops should never exceed 21 in. The tank should be inspected at least once a week in order that any deterioration may be observed, and, when new tanks are installed, see that the work is done in strict accordance with the recommendations of this exchange. Constant supervision and thorough maintenance are the only safeguards against accident.”

The Birmingham, Ala., Waterworks company has won the suit in the Supreme court for collecting back dues from the consumers who refused to pay for the water used in sprinkling lawns on the ground that such was a domestic use. The consumers must now pay back rents.