LETTERS TO THE EDITOR Engineers deserve due regard for their know-

Were Mr. Smith a mining engineer, he would know that some mines can and do operate without concentrators. But no concentrator can operate without a productive mine not very far away. Indeed, a partial attempt to do the latter seems to have been behind many of the recent failures of new projects cited by Mr. Smith in his letter (T.N.M., Oct. 15/90). Too often is an oversized and expensive concentrator constructed without an adequate regard for the associated mine’s ability to deliver. Hugh Taylor, P.Eng. North Vancouver, B.C.