William Dyce Cay

William Dyce Cay, MICE FRSE (28 March 1838 – 13 December 1925) was a Scottish civil engineer.

[2] He was born the son of Robert Dundas Cay, an Edinburgh lawyer, and Isabella Dyce (1811–1852).

In 1844 the family moved to Hong Kong following his father's appointment as Registrar to the Supreme Court of that city.

His mother died there as the result of injuries from a carriage accident in 1852 and is buried in the Happy Valley Cemetery in Victoria, Hong Kong.

[4] He then moved to Belfast to serve as an apprentice engineer under Lord Kelvin's brother, James Thomson.