The double-row self-aligning roller bearing is also used for the largest rotary kiln in the world?in operation in this country. The load on the four pairs of supporting rollers is 480 tons. A Lancashire mill 500 h.p. steam engine had a spherical roller bearing fitted to the connecting-rod big-end in 1921. Prior to this, 1 1/2 gallons of oil per day were required for the plain bearing but after converting to roller bearings only 1 pint of oil per week was necessary. At the same time, speed was increased from 64 to 70 r.p.m. and occasionally the output was increased to 750 h.p. According to the latest information it is still functioning. Three thrust ball bearings 37 1/2 O.D. to take a load of 200 tons each at 30 r.p.m. were fitted to buffer-heading presses in Sheffield. After 25 years' continuous service they are still giving satisfaction.