Laxey Wheel Laxey Wheel The Laxey Wheel (also known as Lady Isabella) is built into the hillside above the village of Laxey in the Isle of Man. It is the largest working waterwheel in the world. Designed by Robert Casement, the wheel has a diameter, is wide and revolves at approximately three revolutions per minute. It was built in 1854 to pump water from the Glen Mooar part of the Great Laxey Mines industrial complex. It was named "Lady Isabella" after the wife of Lieutenant Governor Charles Hope, who was the island's governor at that time. The 150th anniversary of the Lady
Largest known prime number the progression of the largest known prime number in ascending order. Here M = 2 − 1 is the Mersenne number with exponent "n". The longest record-holder known was M = 524,287, which was the largest known prime for 144 years. No records are known before 1456. GIMPS found the fourteen latest records (all of them Mersenne primes) on ordinary computers operated by participants around the world. A list of the 5,000 largest known primes is maintained by Chris K. Caldwell, of which the twenty largest are listed below. Largest known prime number The largest known prime number () is