thanks very much for sorting Anne.

Post February 1884 i.e. after the lozenge years, almost all Registrations - from the total of thirteen categories - are grouped in the same Representations Books, and there are a number of them........ and anyone going through the books systematically would find all glass Registrations no matter what CLASS they were entered under. It's a shame that this 'mixing' of CLASSES was approved - obviously it's so much easier to search when you have one CLASS (material) per book as was the case prior to 1884. It's a situation that possibly came about due to the vast increasing quantity of inventions throughout all the utility materials of wood, glass, linen, lace, ceramics, metal etc. in the latter part of the C19.
It is tempting to short circuit the process, and investigate only those Nos. shown in the Blue Book - which is possibly how Neil may have compiled his Burtles Tate list ......... thus missing 'wayward' Registrations such as this cruciform candlestick example, but having said that I'm unsure as to how the contents of the Blue Book were put together.
It is extremely time consuming to turn every page in some of the Representations Books - some of the older volumes are exceptionally heavy, and a trolley service is offered to readers who lack stamina - it's easy to understand that the prohibitively time consuming process of pouring over every volume, can deter people from thorough investigations.
Registrations for later years are easier in the sense that ledgers are dispensed with and all of the photos - with stiff card backing - are contained within strong paper envelopes - which makes it less arduous physically, but since there are fewer items per envelope then it increases the toing and froing requests to the workers at Kew.
I suspect there are only a few glass items entered under CLASS IV (compared with the overall quantity of CLASS III Registrations), but unless all pages of the Registers are viewed by researchers then there is the potential to miss a glass item classified wrongly as CLASS IV. It appears possible that the Blue Book list may have been compiled in some way from CLASS III items only.
Looking forward to seeing some of Fred's 'elusive' (presumably CLASS IV) designs in the coming days - I've asked Kew to keep my seat warm
