Pen Blathaon

   Pen or Penrhyn Blathaon (proposed as Caithness in Scotland) is stated to be the extreme point from Penwaeth or Pengwaed, in Cornwall, from which it was distant nine hundred miles. The distance between these two places was determined by Dyvynwal Moelmud. In the Welsh Laws is given the following passage, relating to the measurement of the island made by him.-
"Before the Saxons seized the crown of London and the sceptre, Dyvynwal Moelmud was King of this Island; and he was the Earl of Cornwall, by the daughter of the King of Lloegr. And after the male line of inheritance became extinct, he came into the possession of the kingdom, by the distaff (that is by the female line), as being the grandson of the King. Now he was a man of great wisdom, and he first made laws for this Island, and those laws continued to the time of Howel Dda, the son of Cadell. And afterwards Howel Dda made new laws, and changed some of the laws of Dyvynwal. But Howel did not alter the measurements of the lands of this Island, but left them as Dyvynwal framed them; for he was an excellent measurer. He measured this Island from the Promontory of Blathaon, in North Britain, to the Promontory of Pengwaed, in Cornwall, which is nine hundred miles, and that is the length of the Island, and from Crngyll, in Anglesey, to Sorram (Shoreham) on the shore of the sea of Udd (the Channel), that is the breadth of the Island. And the reason of his measuring it was to know the number of miles in his journeys.
   "And this measurement Dyvynwal made by a Grain of barley. Three lengths of a barley corn in an inch, three inches in a handbreadth, three handbreadthe in a foot, three feet in a step, three steps in a jump, three jumps in a land, which is in later Welsh a ridge, and a thousand lands or ridges make a mile, and this measure is used here till now."