Coming-of age of Henry Beyer Robertson (later Sir) (1862-1948), son of Henry Robertson, Palé Hall, Llandderfel
see Wikipedia articles re: both father and son, also:

https://papuraunewydd.llyfrgell.cymru/view/3290248/3290251/12/robertson
- long article in the Llangollen Advertiser (Fri. 17 Aug 1883 p.3 cols 1-4) describing the celebrations, which had been postponed from May until August (HBR was abroad at that time)
"....Tea was given to all the schools of the district, and to a number of the poor and old, while 300 china mugs bearing the inscription, "Majority of H. B. Robertson, Esq., May 4th, 1883," were distributed as mementoes of the interesting event...."

further info about the event:
https://papuraunewydd.llyfrgell.cymru/view/4590196/4590202/55/robertson
https://papuraunewydd.llyfrgell.cymru/view/4590187/4590192/33/robertson
("...In the village of Llanderfel tea was given to the school children and old people, a large number of packages of tea were also distributed, and about 300 china mugs bearing the commemorative inscription, "Majority of H. Beyer Robertson, May 4th 1883...."