 By the standards of the day, these offices were very modern, with radiators, air vents, and the latest fixtures and fittings, and modern communication systems, including telephone and pneumatic tubes were often installed.As a result, many businesses chose to move out of their older, low-rise offices in Chicago to take up tenancy in the new skyscrapers, which were felt to be more convenient and healthier.The first skyscrapers were mainly occupied by male workers, but this changed during the 1890s, with female employees becoming more common.