asked the Secretary of State for Defence what proportion, in value terms of flat gauge glasses are purchased for RN ships in the United Kingdom; and what proportion, in value terms are imported.

I have taken "flat gauge glasses" to mean the glass cover of temperature/pressure measuring gauges. My Department normally purchases measuring gauges as complete units, inclusive of glass facings, and maintains only a very small range of separate replacement glasses. The turnover of gauge glasses is very small, and orders are infrequent, amounting to not more than £400 a year. All orders for gauge glasses are placed, following normal contract practice, with United Kingdom contractors and none is imported direct.