 Van de Graaff applied for a second patent during December 1931, which was assigned to Massachusetts Institute of Technology in exchange for a share of net income; the patent was later granted.During 1933, Van de Graaff built a 40-ft (12-m) model at MIT's Round Hill facility, the use of which was donated by Colonel Edward H. R. Green.One of Van de Graaff's accelerators used two charged domes of sufficient size that each of the domes had laboratories inside - one to provide the source of the accelerated beam, and the other to analyze the actual experiment.