<ARTICLE> 5 <LEGEND> THIS SCHEDULE CONTAINS SUMMARY INFORMATION EXTRACTED FROM THE CONSOLIDATED BALANCE SHEET AND CONSOLIDATED STATEMENT OF INCOME FILED AS PART OF THE QUARTERLY REPORT ON FORM 10-Q AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH QUARTERLY REPORT ON FORM 10-Q. </LEGEND> <MULTIPLIER> 1,000 <PERIOD-TYPE> 9-MOS <FISCAL-YEAR-END> DEC-31-1997 <PERIOD-END> SEP-30-1997 <CASH> $10,339 <SECURITIES> $0 <RECEIVABLES> $151,967 <ALLOWANCES> $1,510 <INVENTORY> $95,372 <CURRENT-ASSETS> $273,416 <PP&E> $1,180,169 <DEPRECIATION> $682,270 <TOTAL-ASSETS> $864,116 <CURRENT-LIABILITIES> $125,119 <BONDS> $0 <PREFERRED-MANDATORY> $0 <PREFERRED> $0 <COMMON> $554 <OTHER-SE> $539,420 <TOTAL-LIABILITY-AND-EQUITY> $864,116 <SALES> $613,180 <TOTAL-REVENUES> $613,180 <CGS> $416,089 <TOTAL-COSTS> $521,077 <OTHER-EXPENSES> $0 <LOSS-PROVISION> $0 <INTEREST-EXPENSE> $559 <INCOME-PRETAX> $92,383 <INCOME-TAX> $33,295 <INCOME-CONTINUING> $59,088 <DISCONTINUED> $0 <EXTRAORDINARY> $0 <CHANGES> $0 <NET-INCOME> $59,088 <EPS-PRIMARY> $1.06 <EPS-DILUTED> $1.06