William Georg Hepworth (16 December 1846 — 12 April 1916) was organist at the cathedral in Mecklenburgh, Schwerin.
The tune, "O Sanctissima" is a well-known one, often known as the "Sicilian Mariners Hymn." The exact origin of the melody is not known. It appeared in "The European Magazine and London Review," 1792, and "Tattersall's Improved Psalmody," 1794, but the actual "composer" is not known.
It is often sung with the text, "Lord, dismiss us with Thy blessing, fill our hears with joy and peace."
I have no other information on Hepworth, but this, and several other of his works can be found in "The Organists Quarterly Journal of Organ Compositions," published by Novello, and edited by William Spark, organist of Leeds Town Hall.
In the "Variations on 'O Sanctissima'" there is an introduction, and five variations. The writing is attractive, and reminded me of the "typical" 19th century variation format. The registrations are designed to further show the sounds and colors of the Armley Schulze. I'll be talking more about this in detail in the upcoming sample set review, "Speaking English with a German accent," soon to be published on "The Barde."
The score is attached below, as well as several photos of the cathedral at Mecklenburgh. This ancient church was built as a Roman Catholic establishment, but has long since become a center of Lutheran worship.
It is ancient and magnificent, and well-worth taking a look at the attached photos. :-)