For the second straight day, the only thing sizzling at the 78th U.S. Open was the weather. A gallery of 23,235 turned out in near 90-degree heat to see if anyone could bust loose from the grip of the Cherry Hills course. No one did.

Andy North wrestled the lead from Hale Irwin with another one-under-par 70. Irwin, who shot 69 Thursday, hit a sand wedge into the water on 17 for a double bogey 7 and settled for 74-143 compared to North's two-under 140. North sank a 30-foot putt for a birdie on the last hole. He was the only player under par at the midway point.

Jesse Caryle Snead, 'Slammin Sammy's nephew better known as "J.C." was the only member of the 153-man field to have a chance of tying or going ahead of North in the late afternoon. But he faded on the tough closing hole and wound up at 72-142 in a three-way tie with Jack Nicklaus and Gary Player.

Nicklaus had a 69, Player a 71. Lee Trevino stayed very much in contention with a 71 for a 143 total.

Bob Clampett, the 18-year-old amateur from Brigham Young University, tacked a 73 onto his first-round 70 to be three strokes behind North.

Joe Inman and Peter Oosterhuis were at 72-72 - 144.

Mark Hayes was even-par leaving the 18th tee.

Four old pros - Nicklaus, Trevino, Billy Casper and Gene Little - dominated yesterday's early action.

Nicklaus was happy with his 69. "Any time you're even after two rounds of a U.S. Open you're not in bad shape; you're in a reasonably strong position," the three-time Open champion declared.

Birdies on the third, fourth and fifth hole more than offset his only bogey, on the first hole.

"The course was set up a little easier," Nicklaus observed. "The cups were in a more reachable position. But we're still playing position and areas - and the wind - out there. We're hitting one-irons and three woods to reach those key positions. The difference is that, at sea level, we'd be hitting drivers to reach those areas at these distances."

Nicklaus used his driver only four times yesterday, on the fifth, 10th, 11th and 17th. He was lucky to escape with par at 14, after having pushed a three-wood into the right rough. He stopped a seven-iron to 30 yards in front of the green, then hit a sand lodge too sharply.

"The ball was going to go at least 10 to 12 feet past the pin," Nicklaus admitted, "but it hit the stick and dropped almost straight, leaving me with a three-footer."

Little, playing in the threesome as Nicklaus, was one under for the tournament and three-under for the round through the front nine, only to see his game fall apart with 42 on the par-36 backside.

The 48-year-old's troubles began on the 13th. His approach shot landed in the creek guarding the front of the green. The 1961 Open victor dropped back, to approach again, and caught a front trap, winding up with a double-bogey six. Another double bogey, on the next hole, put Littler out of contention in a hurry. He caught the nough and two traps on 147.

Casper, who will be 47 next week, eagled the third hole to briefly tie for the tournament lead at two under.

"The Friendly Ghost" - it's been a long time since his 1959 and 1966 Open chipped in a wedge shot from more than 90 yards off the green, to the delight of the morning's largest early gallery. The portly putt-master was unable to stand prosperity, gradually fading in the heat and under the presssure to wind up with six straight bogeys at 76-147.

Trevino, playing with Casper, held on much better for 71 to go with his opening-days 72.

"I hit two bunkers, for bogeys, on 13 and 15, or I'd have had an excellent round," the 1968 and 1971 Open king declared. "I've not been able to charge putts here. The course is fast and the greens are getting faster. They are watering the fairways, not the greens, which means the scores will stay high.

"I'll have to get in better putting position. On Bermuda, you can charge a putt and, if you miss it, go two feet past. Here, if you charge from 12 feet you're likely to be looking at eight feet coming back."

Andy Bean and Dave Stockton could easily have bettered their 144 totals.

Bean, bidding for a third tournament victory in three weeks, "was like a yo-yo . . . playing well, but selecting a few wrong clubs." He was two under through 32 (or 14) with three straight bridies, only to double bogey the 15th and 17th and bogey the tortuous 18th.

"I hit only two bad shots," Bean remarked. "The one was too long, on 15, and other was too short (into the water) on 17. But I'm gonna be there when this is all over. I'm hitting the ball as good as you can possibly hit it."

Bean is 72-72.

Stockton (71-73) needs only to play the 18th better to become formidable. He bogeyed the 480-yard closing hole Thursday and came back with a double bogey yesterday when he sliced his drive into "the tallest grass I've seen all week." His first attempt from the rough advance 30 yards. On the green in four, Stockton two-putted from 15 feet.

The 18th, with a lake on the left, a steep slant to the fairway, and four-inch high rough to the right, continued to play monstrously.

"That hole, and the 17th (a par-5 with an island green) are the prime holes." Arnold (76-75) Palmer observed. "If you're out of the fairway you'll have to one putt for par, and the fairways don't give youmuch room."