Laxey Mine ton, and this would be used to glaze lower end earthenware. During the height of prosperity of the Great Laxey Mine, the Laxey Wheel was erected. The wheel was named the Lady Isabella, after the wife of Sir Charles Hope, who at the time was the Lieutenant Governor of the Isle of Man. During its working life the wheel was capable of pumping 250 gallons of water a minute from a depth of 200 fathoms. By the beginning of the 20th Century the yield from the mine had begun to decline dramatically. During the first six months of 1900 the
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