_City Debts._--For the construction of permanent improvements, the erection of public buildings, and the establishment of commercial enterprises such as waterworks and gas works, cities must borrow money; and so one of the powers always given them is that of incurring debts. This power, however, was greatly abused in the early history of our municipal development--so much so that many cities found themselves on the verge of bankruptcy. In order to check this evil, many states have placed a limit upon the municipal borrowing power, and some have provided that whenever a debt is incurred, provision shall be made at the same time for payment of the interest and the principal within a certain period of years. The debt limit is usually a certain percentage of the assessed valuation of the taxable property within the city. It ranges from 2 per cent in Boston, to 10 per cent in New York. In some cases the limit is so low that cities have been handicapped in constructing needed permanent improvements. Thus in Chicago, where property has been assessed at only one fifth of its real value, the result of the debt limitation has been to render extensive improvements very difficult, and to compel the city to meet the expense of many absolutely necessary undertakings out of its current revenues when the cost should have been distributed over a period of years. Chicago, as a consequence, has the smallest debt of any of the large cities of the country. =Police Protection.=--Where large numbers of people are living together in close proximity the problem of maintaining order and preventing some from violating the rights of others is very much greater than in sparsely settled rural communities. One of the principal tasks of the authorities in a city, therefore, is to provide police protection for the inhabitants. This is done through the agency of a body of men organized and uniformed somewhat after the manner of an army. The size of this force varies ordinarily in proportion to the population of the city. In New York city, for example, the entire police force numbers more than 10,000 men--a body as large as the army of the United States was in the early days of our history. In Chicago there are altogether some 8,000 men in the police service of the city.