<ARTICLE>                     5
       
                                              
<RESTATED>
<PERIOD-TYPE>                      6-MOS            9-MOS
<FISCAL-YEAR-END>                  DEC-31-1997      DEC-31-1997
<PERIOD-END>                       JUN-30-1997      SEP-30-1997
<CASH>                                  41,400           53,100
<SECURITIES>                                 0                0
<RECEIVABLES>                           70,800           62,400
<ALLOWANCES>                                 0                0
<INVENTORY>                             40,100           39,600
<CURRENT-ASSETS>                        15,400           19,500
<PP&E>                                 428,300          431,600
<DEPRECIATION>                         226,900          231,700
<TOTAL-ASSETS>                         475,600          485,800
<CURRENT-LIABILITIES>                   64,200           66,400
<BONDS>                                 89,100           88,000
<PREFERRED-MANDATORY>                        0                0
<PREFERRED>                                  0                0
<COMMON>                                 4,200            4,200
<OTHER-SE>                             255,200          270,600
<TOTAL-LIABILITY-AND-EQUITY>           475,600          485,800
<SALES>                                237,800          343,000
<TOTAL-REVENUES>                       237,800          343,000
<CGS>                                  168,800          244,800
<TOTAL-COSTS>                          168,800          244,800
<OTHER-EXPENSES>                          (500)         (1,400)
<LOSS-PROVISION>                             0                0
<INTEREST-EXPENSE>                       2,800            4,200
<INCOME-PRETAX>                         29,600           42,000
<INCOME-TAX>                            11,300            6,700
<INCOME-CONTINUING>                     18,200           35,200
<DISCONTINUED>                               0                0
<EXTRAORDINARY>                              0                0
<CHANGES>                                    0                0
<NET-INCOME>                            18,500           35,200
<EPS-PRIMARY>                             1.12             2.18
<EPS-DILUTED>                             1.12             2.18