In the larger cities other hygienic measures demand attention, such as provisions for parks and playgrounds, the proper housing of the poor of the city, and the suppression of the smoke and dust nuisances. Crowded together as people are in the cities, the welfare of each individual depends in a large measure upon the welfare of all. Hence the problems of public sanitation are matters in which all are vitally concerned. *Sanitary Conditions of the Home.*—The home, being the feeding and resting place for the entire family, is the most important factor in one’s physical, as well as moral, environment. For this reason there is no place where careful attention to hygienic requirements will yield better results. Much of the danger from germs may be prevented by instituting and maintaining proper sanitary conditions in and about the home. One of the first requisites of the home is a suitable location for the house. The house should be built upon ground that is well drained, and if natural drainage be lacking, artificial drainage must be supplied. It should not be situated nearer than a quarter of a mile to any marsh or swamp and, if so near as that, it ought to be on the side from which the wind usually blows. A stone foundation should be provided, and at least eighteen inches of ventilated air space should be left between the ground and the floor. Ample provisions must be made for pure air and sunlight in all the rooms. The cellar, if one is desired, needs to be constructed with special care. It should be perfectly dry and provided with windows for light and ventilation. Adequate means must also be provided, by sewage pipes and other methods, for the disposal of all waste. Where drainage pipes are provided, care must be taken to prevent the entrance of sewer gas into the house and also the passage of material from these pipes into the water supply. The placing and connecting of sewer pipes should, of course, be under the direction of a plumber. *The Water Supply.*—Since water readily takes up and holds the impurities with which it comes in contact, it should be exposed as little as possible in the process of collecting. Where cistern water is used, care must be taken to prevent filth from the roof (Fig. 168), water pipes, or soil from getting into the reservoir. Water should be collected from the roof only after it has rained long enough for the roof and pipes to have been thoroughly cleaned. The cistern should have no leaks (Fig. 169), and the top should be tightly closed to prevent the entrance of small animals and rubbish. [Fig. 168] Fig. 168—*Contamination of cistern water* by birds nesting in the gutter trough.