This little stone culvert is situated to the North end of the Mill House at Blantyre Works, but actually within the David Livingstone Centre lower gardens. It once was located on the South East side of the Rose Garden, which was a flat, level area high above the lade. The construction does not date to the time of the Blantyre Mills itself, but instead relates to the 1929 renovation where water was brought from a higher level at Shuttle Row, down into the Rose Garden itself, either as a water feature, or most likely a source for the gardener to get water, without having to climb the steps back and forth. I photographed it in June 2015, but it looks a little filled in.
Of course the Rose Garden is not there anymore. In more modern times, a tap has been run into it, again likely to have the same watering purpose. It is not shown on any map and is situated immediately below the gable of Shuttle Row, down at the lower level of the Africa Gardens.