Laxey Wheel Isabella was celebrated by the people of Laxey with a grand fayre on Saturday 24 September 2004. It is currently maintained by Manx National Heritage as part of the Great Laxey Wheel & Mines Trail. The wheel features today on the reverse side of the £20 notes issued by the Isle of Man Government. A water-powered wheel was used because the Isle of Man does not have a supply of coal for a steam-powered pump. Water from the surrounding area – including a number of local springs and streams – is collected in a cistern, which is above the level
Largest known prime number Largest known prime number The largest known prime number () is 2 − 1, a number with 23,249,425 digits. It was found by the Great Internet Mersenne Prime Search (GIMPS) in 2017. Euclid proved that there is no largest prime number, and many mathematicians and hobbyists continue to search for large prime numbers. Many of the largest known primes are Mersenne primes. , the seven largest known primes are Mersenne primes. The last sixteen record primes were Mersenne primes. The fast Fourier transform implementation of the Lucas–Lehmer primality test for Mersenne numbers is fast compared to other known primality tests