Onnes purchased a Linde machine for his research. On March 21, 1900, Nikola Tesla was granted a patent for the means for increasing the intensity of electrical oscillations by lowering the temperature, which was caused by lowered resistance. Within this patent it describes the increased intensity and duration of electric oscillations of a low temperature resonating circuit. It is believed that Tesla had intended that Linde's machine would be used to attain the cooling agents.