Ordered that the opinion in this case be amended as follows:

1. Strike from the last line on page 5 the phrase “the Bituminous Coal Act of 1937,”.

2. Strike from the fifth line of page 6 the phrase “, save possibly one,”.

3. Strike footnotes 6 and 9.

4. Renumber the footnotes accordingly.

Opinion reported as amended, ante, p. 357.