Published in 1951 in by the renown glassmakers, the Pilkington Brothers who invented the Float Glass process. The "Ready Reckoner" is a reference manual that discusses "Structural and Special Glasses of British Manufacture", a complete list of "Works, Depots, Offices and Agents" along with 136 pages of "Superficial Measurement" charts. This copy was used by the trade with one specific section obviously referred to the most, as it's somewhat stained and hinged, some pencil and the odd pen notation. Neat row of numbers and a name in ink with the word "direct" stamped twice to the ffep. The boards are moderately stained, the corners are slightly rubbed and bumped. A very scarce title.