"his landscapes were deemed the acme of beauty"
"the artist's gifts are at their acme"
"at the height of her career"
"the peak of perfection"
"summer was at its peak"
"...catapulted Einstein to the pinnacle of fame"
"the summit of his ambition"
"so many highest superlatives achieved by man"
"at the top of his profession"

"all points on the same meridian have the same longitude"

"meridian hour"

"our manhood's prime vigor"