There is a slate sundial affixed over the south porch of the church, bearing the inscription “Joseph Phillips MDCCLVlll” (1758).
George Nicholle has unearthed the following information on sun dials written by C H Cornish, a clockmaker of Plymouth, circa 1910.
Owing to the variation between Sun Time and ordinary Clock Time, a sun dial fixed at Greenwich only indicates correct time four times a year, the dates being 15thApril, 15thJune, 2ndSeptember, 25thDecember.
All sun dials are subject to this error, on some dates the difference in Sun Time and Clock Time at Greenwich amounts to as much as 14½ minutes fast or slow.
Ugborough being situated 3¾ degrees of longitude west of Greenwich, the sun reaches the meridian 15 minutes later; this only permits agreement with the clock once a year on 15th.February. At Ugborough the difference in October amounts to as much as 32 minutes.