 It is believed that Tesla had intended that Linde's machine would be used to attain the cooling agents.A milestone was achieved on July 10, 1908 when Heike Kamerlingh Onnes at Leiden University in the Netherlands produced, for the first time, liquified helium, which has a boiling point of 4.2 kelvins at atmospheric pressure.Heike Kamerlingh Onnes and Jacob Clay reinvestigated Dewar's earlier experiments on the reduction of resistance at low temperatures.