Laxey of the Isle of Man, was built in 1854 to pump water from the Laxey mine shafts. Now a tourist attraction, it remains the largest working waterwheel in the world. Designed by Robert Casement, it is in diameter and wide. It revolves at about 3 rpm. The mines employed over 600 miners at their peak, producing lead, copper, silver and zinc, until they closed in 1929. The Wheel was owned by Edwin Kneale from 1939 to 1965; he saved it from being dismantled and ran it as a tourist attraction, before passing it on to the Manx nation, with the
Table of the largest known graphs of a given diameter and maximal degree Table of the largest known graphs of a given diameter and maximal degree In graph theory, the degree diameter problem is the problem of finding the largest possible graph for a given maximum degree and diameter. The Moore bound sets limits on this, but for many years mathematicians in the field have been interested in a more precise answer. The table below gives current progress on this problem (excluding the case of degree 2, where the largest graphs are cycles with an odd number of vertices). Below is the table of the vertex numbers for the best-known graphs (as of