On the southern walls of many churches in England dials are to be found of a kind which is peculiar to this country. They take the form of a semicircle with lines radiating from the centre, at which there is a. hole for the style or gnomon. This is always missing. They are known as scratch dials, incised sundials, mass clocks, primitive sundials, or sexton's wheels. The earliest known is one on Bewcastle Cross, Cumberland. It is a perfect example of the type, and the date assigned to it is A.D. 675. A diagram of this dial is given in fig. 1.