RON Yates doesn't have a clue about concrete testing, (Citizen letters, April 19).

His letter reads as though they mixed a batch, stood around waiting while a bucket of sloppy concrete was taken to Manchester, and in the meantime, the wet mix in the drum would be beginning to set.

The actual method used was making 6ins cubes of the mix in cast iron moulds, meanwhile use the concrete, when the cubes were set they were placed in a water tank to mature and then taken to a laboratory where they were crushed at seven, 14 and 28 days.

Peter Walmsley, Aspels Crescent, Penwortham, Preston.