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
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