In 1820, The General Society opened one of the City's first free schools as well as the Apprentice's Library. The school which became Mechanics' Institute in 1858, continues to provide tuition-free evening instruction in trades-related education and provides a unique service to the building and construction industry. The Institute is the oldest privately endowed technical school in New York City with more than 180,000 alumni. All Mechanics' Institute instructors are masters in their trades or professions working at their craft during daytime hours and teaching knowledge-driven classes at night. Their expertise gives the students first-hand instruction from qualified teachers with on-the-job-experience. This fall, over 400 students have enrolled in Mechanics' Institute programs including Construction Documents and Design, Electrical Technology, Historic Preservation, Plumbing Design, Project Management and Facilities Management.