Cobb, a 200 pound London fur broker, with a friendly smile pounded through the kilometer at 367.92 miles per hour on the initial sprint, then sped back at 371.59, indicating his acceleration increased as he whizzed along to a well earned victory. Eystons measured mile record was achieved with a north average of 356.44 and a south mark of Greatest Speed Aug 23 1939 The south run kilometer mark of 371.59 m.p.h. was the greatest speed ever reached for a land machine. Cobb traveled 369.23 miles per hour on the north run yesterday only to stall his motors on the return trip. Favored by a cool and quiet dawn, the big Englishman thundered across this dry lake bed in western Utah twice without incident. Smoke and fire poured from the two exhausts atop the trim racers hull as the machine fairly flew between the huge red markers at the start and end of the measured mile. Only a few hundred speed hungry fans witnessed the fall of Eystons record, which was set a day after Cobb had journeyed at 350.2 miles per hour last September. Cobb said the 24 cylinder, three ton car performed perfectly. It was like driving a train, he grinned. As soon as the cap was removed from the tiny cockpit, Cobb wiggled his huge frame out and beamed. He smiled as the crowd cheered the announcement the record had fallen. Cobbs time in seconds: Mile north run, 9.71; south, 9.81; average 9.76. Kilometer north run, 6.08; south 6.02; average, 6.05. Eystons run in seconds: Mile north, 10.07; south, 10.01; average, 10.04. Kilomter north run, 6.25; south, 6.3 average 6.22. For the time being Cobb is satisfied. Let me digest this one first, he declared when asked if he would try to boost his record. Cobb admitted that traveling at such speeds was not a diversion he would care to indulge in every day. Its not particularly frightening, he declared. But theres always the uncertainty when you start out, about whether or not you are going to reach the other end. And I can assure you it is certainly a relief when you do reach that other end and pull up to a safe stop.