Found at Manuel Works, Whitecross by Ian Suddaby.

This example is not in my possession

The manufacturer of this checker is unknown although the find site would suggest it was made at the Manuel Works, Whitecross’ Scotland.

  • Stein, Castlecary Fireclay Works, Castlecary, Stirlingshire.
  • Stein, Manuel Firebrick and Refractory Works, Whitecross, Stirlingshire.
  • Stein & Co, Anchor Brickworks, Denny, Stirlingshire.
  • Milnquarter Fireclay & Gannister Works, Bonnybridge, Stirlingshire.

Ian states –

Manuel Brickworks in Central Scotland produces another interesting find. There’s been lots of these to be honest and the background information/research is usually woefully lacking in detail. Undaunted, I try again.
What is probably a very early McKee type Checker Brick was found, with possibly coal burning residues adhering and a stamp bearing the brand name MICRAL. These items are used in the air preheating systems of furnaces and kilns. Google tells me Micral is a brand name used by JM Huber of Atlanta, Georgia, USA and that it was an additive to various materials that increased their melting points. It makes sense for it to appear on and in fireclay products.
So, for background, a number of Tunnel Kilns for firebricks were built at the Manuel Brickworks in the late 1920s-1940s and most, if not all, were constructed by the Harrop Ceramic Service Company (est. by Carl Harrop in 1919). It might be that Harrop and Huber had a working relationship in the 20s-40s and that the Micral product was added to the Harrop checker bricks to increase their ‘refractoriness’ or working life?
If i search for Micral on the various brick Facebook pages, there are no results, and indeed there is nothing easily available anywhere about the early history of either the Micral brand or JM Huber. This doesn’t surprise me, as Manuel constantly produces new mysteries that don’t have ready answers.
Has anyone heard of Micral? Or any information about Huber and Harrop?
Huber sent a very rapid reply to my email query. They weren’t producing Micral in the 1930s and they also comment that many other companies use the brand name. So Harrop or indeed Stein might be the maker instead. I doubt this will be resolved, no surprise there.


16/07/1932 – The Scotsman … New company – British Ceramic Service Co. (Ltd.), 121 West George Street Glasgow Private company, to act as licensees under an agreement with the Harrop Ceramic Service Company to sell and build continuous kilns and driers and to carry on the business of builders and contractors. Capital, £500, in £1 shares.

Below – 16/07/1935 – Staffordshire Sentinel – Part of a British Ceramic Service Co. (Ltd.) (AKA BRICESCO ) advert with reference to Messers John G Stein and Co and Douglas Firebrick Company.

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