_Work of the Health Department._--Among the principal duties of the health authorities are the inspection and abatement of unsanitary places and the suppression of nuisances; the inspection of public buildings and sometimes of private dwellings with special reference to drainage; the removal of garbage and other refuse (in some cities); the inspection of the city water supply; the inspection of food, particularly milk; the control of certain establishments of an offensive character, such as slaughterhouses, soap factories, and fertilizer factories; the vaccination of school children and often of other persons, as a precaution against smallpox; the isolation and quarantine of persons suffering from contagious diseases; the maintenance of pesthouses and hospitals; and the collection of vital statistics. One great source of disease in cities is impurity of the food supply, especially of milk, and much of the activity of the health department is directed toward the inspection of milk and other food. Crowded, ill-ventilated, and poorly constructed dwellings are another source of disease, and many cities have undertaken to prevent this evil as far as possible through tenement house laws and building regulations requiring dwellings to be constructed according to plans prescribed by law. The enforcement of these laws often devolves upon the health department, which carries out a rigid system of inspection. In recent years much more attention than formerly has been given to the problems of health administration, and great improvement has been made. So efficient is the health administration of some of our large cities that the death rate in proportion to the population is actually lower than it is in many small country towns where little or no attention is paid to this important branch of administration. =Fire Protection.=--The danger from fire, like that from disease, is obviously greater in crowded cities than in country districts. Therefore, every large city and most small ones maintain an organized fire department. In the days of small cities reliance upon voluntary unpaid fire companies was the rule, and this is true even to-day in many of the smaller towns and cities. In the larger cities, however, there are organized professional companies, the members of which give all their time to the service and are paid regular salaries. New York city has more than 5,000 men in its fire department, some 900 pieces of apparatus including more than a dozen fire boats, and hundreds of thousands of feet of hose. At the head of the department there is usually an official called a fire chief or fire marshal, appointed by the mayor. The rank and file of the department are under civil service rules, the employment is of a permanent character, and many cities have provided a system of pensions for members who have grown old or are disabled from injuries.