W. A. (Tony) Boyle, international president of the United Mine Workers of America, said he has been informed by the Post Office Department that hard coal will be used to heat a new post office to be constructed in Nesquehoning. Boyle, who has been spearheading a campaign for the utilization of anthracite in federal and state institutions, said the decision is "encouraging to mine workers of the Panther Valley and to the economy of the area as a whole."