Technician demonstrates the Cobalt-60 Beam Therapy Unit to a group of children in foreground; male [teacher] at far left.

Bio/Historical Note: This Cobalt-60 unit was constructed for the Saskatchewan Cancer Commission and was installed at University Hospital in August 1951. It was the first Cobalt-60 Unit placed in operation anywhere in the world. The unit was designed by Dr. Harold Johns of the U of S Physics Department in collaboration with Dr. T.A. Watson of the Cancer Clinic. The unit was constructed by J.A. MacKay of the Acme Machine and Electric Co., Saskatoon. A number of graduate students in physics and chemistry have carried on important research projects with the unit. The source contains 1,100 curies of cobalt and was produced in Canada's atomic pile in Chalk River, Ontario. This source is equivalent in power in about 1,500 grams of radium. This is about 1,500 times as much activity as is presently in use for other medical purposes in Saskatchewan. The radiation from the Cobalt-60 Unit, because of its great penetrating power, must be shielded by about ten inches of lead. This penetrating power makes it ideal for reaching tumours beneath the surface of the skin.
From The Green and White, fall 1953, pg. 1.