This is an age of surprises and scientific researches. The up-to-date vacuum-cleaning machine is a huge debt to an ancient past. It is a big improvement over the methods employed in days gone by. As a preventive for moths, it has no equal. In hotels where this labor-saving device has not been installed, carpets must be carried to the roof to be cleaned, or sent to the regular carpet-cleaners, and soon converted into ravelings. Carpets are very expensive, and, if you want your money's worth from them, you must preserve them from moths. In order to do this, they must be either vacuum-cleaned or taken to the roof every six months and given a beating. After the moths get a start in a carpet it is surprising to learn what vast inroads toward destruction they can make in a few weeks. Moving the furniture and thoroughly sweeping and brushing the edges with turpentine are good preventives. But nothing will so effectually destroy them as does the vacuum-cleaning process. In order to secure detailed information regarding the workings of the vacuum-cleaning system for hotels, I wrote to a gentleman in Milwaukee, who is probably the best informed man on that subject in the country. Besides being in the vacuum-cleaning business, he is a hotel man himself and therefore knows how to meet the needs of the hotel housekeeper. I quote a part of his reply: _System Explained by an Expert._ "The vacuum-cleaning system in a hotel will pay for itself every year by reducing the cleaning force and by increasing the life of carpets, rugs, hangings, upholstery, and decorations, whether paper, fresco, or paint. "In hotels where this system is in use--and their number is increasing every month--carpets and rugs are cleaned on the floor. Right here is a big saving. First, taking up and relaying carpets is expensive. There is nothing that wears them out quicker than this sort of handling and the beating and "tumbling." Vacuum-cleaning not only saves this, but saves the daily wear and tear of grinding in the dirt and wearing off the nap with a broom. Third, with the vacuum-system, valuable rooms are never put out of commission while the carpets and rugs are away being cleaned. "Not only are the carpets and rugs kept cleaner by the vacuum-system, but everything else is cleaner because dust is kept down. The housekeeper of a certain hotel told the owner that since he put in the vacuum-system, the transoms had to be washed only one-fourth as often as before. Now, the dust on those transoms came out of the air. It settled everywhere, but it showed plainly only on the transoms. With the vacuum-system, there is only one-fourth as much dust to settle on the walls and decorations, and even that little is quickly removed with the vacuum-wall-brush. Dust on the walls is what causes the unpleasant, musty smell of many hotel rooms. Keeping walls clean means less frequent redecorating. _Purifies Nearly Everything._