What was now needed was a steady supply of high-quality iron from which the wire could be manufactured. In 1567, Humfrey succeeded in obtaining the services of an expert in the production of Osmond iron from the south-western part of Westphalia, in northern Germany. This expert arrived in Wales in 1567 and began working at a forge located in Rhyd-y-Gwern, a hamlet in the Glamorganshire part of the parish of Machen, about 20 miles southwest of the Tintern wireworks. The expert’s name was later provided in Humfrey’s letter of 24 August 1577:  'one Corslett, a German born who at his coming over into this realm first devised more commodius engines than ever before was known or used in England…engines, tools and devices as were first used and invented by the said Corslet, for the making and hoosing of Osmond iron…' According to historian H.R. Schubert, the full name of this expert was Corslett Tinkhaus of Westphalia, Germany. Wales (especially Glamorgan), England, United States, Canada, New Zealand, South Africa, Australia. Prominent or famous people having Coslett or a variant as a surname, first name or middle name are as follows: