Glass Types and Measures

with concave oblong circular figures on one side. There were various types of pattern. Itwassoldinsquares, of 12 or 14 inby 15 or 16in.

WEIGHTS AND QUANTITIES

These may conflict with information gleaned by other researchers, as measures and quantities seem to have varied at different periods (and possibly in different places).

~ Crib: a hundredweight or 150 sq feet.

II] Case: 24 leaves, half cases also sold, of 12 leaves. Neve - a case ranged from 25 tables (French glass) to 45 of Newcastle. This dependent on diameter of the table:

those 5 square foot were 45 to the case, at 6 square foot there were 35.

~ Table or leaf: each unit of glass, uncut, e.g. circles, or segmentally headed rectangles in broad glass. According to Neve, tables of crown were 3 ft 6 in or 3 ft 8 in, giving area of 9-10 ft2. The case then had aquantityof 220-240 ft2. Tables of crown became larger during the 18th century,

measuring up to 5 ft and 6 ft in diameter. ~ Webb or way: this peculiar term to describe a quantity of glass seems to have been applied only in regard to Rhenish glass. Each webb consisted of bunches of six glass plates of about two square foot. At the end of the 17th centurythere were 100 bunches per webb, but later 60 was the usual amount.

~ Squares: the commontermto describe a rectangular pane of glass in timber casements or sashes. Very often building accounts only mention the term without givingexactsizes. Sometimesthisiselaborated upon - the general sizes being from 6inby8inupwards, with l9inby 12 in and 12 in by 16 in usual. Though most panes were rectangular, square ones are also found.

~ Quarries: Neve gives details about calculatingsizesofquarries, andthe standards used, which would be of relevance to anyone needing to calculate exact measurements but are nc~tnecessaryhere. Suffice to mention that there were two

types, ordinary and long, and that the most usual size was 12s (meaning that thereare 12 of l2sinafootofglass); these are 6 in long by ~ in wide.

~ Measuring glass according to weight:

Neve quotes a Mr Leybourn as stating that225ftofglass equals about 200 lb, i.e. 9 ft is about 8 lb weight. In an article whichmentionedthat the chapelin Dublin Castle bought 600 lb of glassinthe late 14th century, the author quotes the then (1920s) clerk of works atYorkMinsteras estimating 3 lb per foot of glass. The discrepancy is interesting and may be explained by extreme thinness of good crown, which weighs less per foot.

It is hoped that this short explanation of types and terms may be of some use to those who come into contact with this most aesthetic of materials. I am very interested in any other information on this subject, or others linked to it, if anyone has snippets orknows of obscure sources that I may have missed.

Nessa Roche is based in Dublin