Duane Doty, formerly of this city, now of Pullman, 111., has a descriptive article of Pullman in the Arcade Journal, of Pullman, 111, on the sewerage question, which is just now uppermost in Ann Arbor. He writes as follows: AN AGE OF CITIES. In this age of city building the question of the proper sewerage of towns has become one of great and growing importance. Twenty-five per cent. of the population of our country resides in cities having a population of 10,000 and upward, but when we include those who reside in smaller towns, villages and hamlets, we find not less than 40 per cent. of our population urban in character. A recent letter from Supt. Porter, of the Census Bureau, stetes that there are now 447 cities in the United States each of which has a population of 8,000 and upward. Sanitary questions are now the most vital ones with which cities, villages and hamlets have to deal. And these questions are everywhere attracting deep and earnest attention. As yet residents of Pullman do not own their homes, but lease them from the company; but it is the intention to permit them to purchase homes in the near future. IMPORTANCK OF SEWERAGE. When any territory becomes densely settled, like Massachusetts, people readily begin to see and understand the necessity of preventing the pollution of streams and lakes with sewage, and that commonwealth is grappling with this subject in a way that must lead other States, very soon, to make it one of State if not of national interest and action. Just what ought to be done with sewage is by no means a settled question, each locality presenting its peculiar problems for solution. But one thing is well understood and that is, that sewage ought not to be allowed to go into lakes and streams. Among the methods of disposal, and the one of which it is the chief object of this article to speak, is that of land purification. It is an old process, traces of it being found in the ruins of ancient Nineveh. THE GROWTH OF A TOWN. Here, for the first time in the building of cities, the drainage and sewerage preceded the population. The ordinary small city is a ard collection of buildings, whose inartistic forms and relations would, as likely as not, be improved by an earthquake. The inhabitants of such places, at the outset, have no more ideas or knowledge of sanitary needs than Laplanders, and not until the whole soil of the place becomes saturated with the accumulated filth of years, and an epidemie improves society by removing the pachyderms and amphibious bipeds, and with them some whose lives could not well be spared, do those who are left realize the necessity of sewerage, and adopt some imperfect and inadequate method of relief. SEWERAGE PIPING HERE. The great value of the work done here is principally suggestive, and is studied by travelers and scientific men of every continent. At the outset it was decided that it would never do' to permit sewage to flow into Lake Calumet, as it would make a cesspool of that body of water, and to obvíate such a result, the mode of disposing of the Pullman sewage here outlined was decided upon, and pipes were laid in every other street running east and west, and lying between the streets having brick mains for atmospheric water; these sewers are raade with vitrified pipe, laid deep tnough to run under all surface drains which, as laterals, lead into main sewers running north and south to a reservoir under the Water Tower, which they enter at sixteen feet below the surface of the ground. These sewer pipes vary from six to eighteen inches in diameter. The lateral pipe for carrying the sewage of a block of dwellings runs in the alley and is only six inches in diameter, and has a fall of from four to five inches in a hundred feet. The smallness of these laterals insures ascourwhichkeeps them clean, but provisión has been made for flushing the pipes should they require it. Service pipes from houses and lots, provided with suitable catch-basins in the rear of dwellings, each basin connected with from four to six houses, convey the sewage from sinks and closets to these alley laterals. THE RESERVOIR. The sewage goes by gravity from buildings to the reservoir under the Water Tower. This reservoir is 60 feet in diameter and 15 feet deep, and holds over 300,000 gallons. The sewage is pumped from it as fast as received, and before sufficient time elapses for fermentation to take place. Standing over the reservoir the visitor never detects anything unpleasant, the airbeing just as pure as it is in the Corliss engine room, the only odor being that from the oil used about the pumps. THE SEWAGE. I he sewage from dwelhngs averages probably from 120 to 130 gallons a day for each person of the population. Of the 1,800,000 gallons pumped every twenty-four hours (the daily average for 1890), the excess above the amount coming from dwellings is from the shops and factories. This seems a large amount of sewage for a population of 11,000, but when it is remembered that every tenement in the city is provided with the best of water closets and sinks, that the faucets for obtaining water are all inside the houses, and that about ten per cent. of the dwellings are provided with bathrooms, it will be seen that a large amount of sewage per capita is unavoidable. FARM END OF IRON SEWAGE PIPE. The sewage is pumped from the reservoir through a twenty-inch cast iron pipe to a sewage farm about three miles south of the city. At the farm end of this pipe the sewage goes into a receiving tank made of boiler iron, which is set a few feet above the surface of the ground. Through the center of this tank there is a screen in an oblique position, through the meshes of which substances more than half an inch in diameter cannot pass and get into the piping in the farm. The sewage waters pass through this screen and thence into the distributing pipes, a pressure of not more than ten pounds being allowed upon those pipes. THE SEWAGE FARM AND ITS PIPING. One hundred and forty acres of land have been thoroughly piped and underdrained for the reception and purification of sewage with which these acres are irrigated. Hydrants are placed at suitable intervals so that the distribution can be conveniently effected. All organic matter in the sewage is taken up by the soil and the growing vegetation, and the water, making from 200 to 600 parts of the sewage, runs off through underdrains to ditches which carry these filtered waters into Lake Calumet . Where the sewage water, purified by filtering through the soil, leaves the drains, it is as clear and sparkling as sparkling as spring water, and purer than the water from the surface wells used by people on neighboring farms. In winter the sewage runs upon one field or upon one filter bed and then upon another, the filtering processes appearing as perfect as in summer. Thus are waste producís utilized, being largely transmuted by vital chemistry into luxunant vegetable forms. The most profitable crops for this farm have been found to be onions, cabbage and celery. In Europe the question is, at how little expense can such a farm be operated, the primary object being the necessary disposal of sewage; and the proceeds from crops raised merely diminishing operating expenses. A European sewage farm operated at a profit is the exception and not the rule. COST OF OPERATING THE PUMPS. The cost of operating one of these pumps for twenty hours and pumping 1,800,000 gallons of sewage isas follows: Cost of coal used $1.73 Cost of oil and waste 57 Engineer's wages 3.75 Total $6.05 This is a trifle less than 33 cents for pumping 100,000 gallons. During the months of last September, October, and November the daily average of sewage pumped was a little over 2,000,000 gallons.