The proprietors of the dance halls in question have "open dates," on which their halls may be rented by social clubs or other organizations for the purpose of giving an "affair" or a "racket," as a ball is sometimes called. There are hundreds of these clubs and organizations in New York City, and the chief feature of the year's activity is the giving of a ball which all the friends of the members are expected to attend. Their membership lists are made up of cliques or gangs of young boys and men who come together because of some mutual interest, sometimes for worthy motives, but very often as a cover for disorderly and even criminal purposes. Between some of these groups there is great rivalry, at times leading to fights and disturbances. The usual method of advertising dances is by distributing "throw aways" or small colored cards on which are printed, not only the name of the group giving the dance, but also the choruses of popular songs, parodies, or verses. These latter intimate the character of the proposed frolic. They all appeal to the sex interest, some being so suggestive that they are absolutely indecent. During the progress of a dance in St. Mark's Place,[88] a young girl, hardly above seventeen years of age, presented a boy with a printed card advertising a ball soon to be held. When the card is folded, it forms an obscene picture and title. During the past few years aggressive measures have been taken by different reform organizations aiming to bring about a more wholesome atmosphere in connection with public dances, especially those attended by poorer boys and girls. Proprietors have been induced to employ special officers to attend the dances and keep order, prevent "tough" and "half-time" dancing, and protect innocent girls from the advances of undesirable persons. The duties of the special officer are difficult to perform. If he interferes too much, the dancers go to some other place where they enjoy more freedom. As a result, the honest proprietor who endeavors to conduct a respectable hall loses patronage, while the disreputable owner makes all the profit. Again, the young people who attend these balls know immediately when a person different from themselves appears in the hall. At once the dance becomes modest and sedate and the visitor goes away to report "that while conditions are not what they should be, yet on the whole there is great improvement."