1 Connecticut Children's Medical Center-Volunteer opportunities are available for anyone who is 13 years old, dependable, and able to commit to at least three hours of service per week for a minimum commitment of one year (six weeks during the Summer period). Children's Hospital Central California-We can match your skills and interests with a volunteer position that meets your needs and ours! 2  Whether it's playing with children in the Child Life Playroom, visiting with family members, or providing clerical support in an office setting, you can make a difference.
Definition of tractor - a powerful motor vehicle with large rear wheels, used chiefly on farms for hauling equipment and trailers. Definition of tractor - a powerful motor vehicle with large rear wheels, used chiefly on farms for hauling equipment and trailers.
A portable engine; a precursor to modern engineering vehicles. An early gasoline-powered tractor. The use of heavy equipment has a long history; the ancient Roman engineer Vitruvius (1st century BCE) gave descriptions of heavy equipment and cranes in ancient Rome in his treatise De architectura. The pile driver was invented around 1500. The first tunnelling shield was patented by Isambard Kingdom Brunel in 1818.