To clarify after its long pipe journey (probably through rusty pipes, etc.); to insure plumbing (in case of the installed filter in the cellar) against clogging, incrustations and general wear, accumulations of material bound to enter the water on its trip through the pipes to the house--due to broken water mains, fires in the city--accidents of any kind; to give the laundry a clean appearance, for the best laundry work availeth little if the water is murky or turbid; to polish water, or render it free from flavor and turbidity. When typhoid had its happy hunting ground in plumbing it was thought quite in keeping to have typhoid cases in abundance. In Pittsburgh and other such afflicted towns it is now felt to be a heinous sin, since filtration has become a part of the service that towns render to their inhabitants. In fact, all boards of health to-day feel it to be a felony and disgrace to find a case of such a disease in the community. So, to public-spirited citizens in unfiltered regions, your task is cut out for you. You can get rid of muddy, dirty water by municipal filtration plants or home filters and care. For those who live in filtered towns the use of filters is manifest, too. There are various kinds of filters in use, but only two kinds are of interest for use in the home. 1. The type affixed to spigot (or water cooler). 2. The installed filter placed in cellar or other part of the home to filter the whole water supply. These are divided into many technical categories, but what you are interested in are the following questions: Do you need a filter? What shall you have to know to buy a filter intelligently? Rapidly stated, it is safest to buy a filter from a manufacturer who says “my filter is not absolutely perfect but it is the nearest thing to perfection we can get. We know our filter can render water from 90 to 100% free from bacteria, as we have had bacteriological tests made by competent chemists.” When you order a filter, put down on paper the answers to the following questions, and send them to the manufacturers who will then give you the data and prices. Choose the best manufacturer and then invest: 1. Are the fixtures all on direct water supply or are they supplied from an open storage tank or combination of the two? 2. What are the source, nature and peculiarities of the water to be filtered? Has it odor, taste, vegetable discoloration, clay or iron stain? 3. What sort of water supply system do you use and what of the water pressure? What is the size of the supply pipe? (Ask your plumber.) 4. How many gallons of water are required to be filtered per minute, per hour or per 8, 10, 12, or 24 hours? (Ask your plumber.) 5. How many bathrooms and other water fixtures are in your home? 6. Is there a municipal plant in your town? What kind?