Little Isabella Little Isabella Little Isabella is a rustic water wheel, situated in Groudle Glen on the Isle of Man, that was originally built in 1893 with the arrival of the Manx Electric Railway to the glen. It has been dubbed the "Little Isabella" owing to its alleged resemblance to the Laxey Wheel in nearby Laxey which was opened in 1854 by Lady Isabella, the wife of the then Lieutenant Governor of the island. In its time the wheel has been used for various purposes, including pumping water to the Groudle Hotel (designed by Hugh Ballie-Scott) and providing power for the fairy
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