Cobalt Teletherapy Unit
In 1951 Canadian scientists, here and in Saskatoon, opened a new front in the battle against cancer. Through a pioneering partnership, the two teams of physicists, physicians and engineers, working independently yet cooperatively, designed the Saskatoon and the Eldorado (London) cobalt teletherapy units. Both became prototypes for the first commercially available units, then called "Cobalt Bombs", which allowed gamma radiation to be focussed directly on cancerous cells. Decades of effective worldwide use have proven the dependability of these units.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.