<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY INFORMATION EXTRACTED FROM THE CONSOLIDATED
BALANCE SHEET AND THE CONSOLIDATED STATEMENT OF INCOME FILED AS PART OF THE
ANNUAL REPORT ON FORM 10-Q AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
ANNUAL REPORT ON FORM 10-Q.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-END>                               MAR-31-1997
<CASH>                                          $2,615
<SECURITIES>                                        $0
<RECEIVABLES>                                 $146,957
<ALLOWANCES>                                    $1,359
<INVENTORY>                                    $91,533
<CURRENT-ASSETS>                              $258,074
<PP&E>                                      $1,152,283
<DEPRECIATION>                                $661,422
<TOTAL-ASSETS>                                $842,146
<CURRENT-LIABILITIES>                         $134,812
<BONDS>                                             $0
<PREFERRED-MANDATORY>                               $0
<PREFERRED>                                         $0
<COMMON>                                          $550
<OTHER-SE>                                    $509,686
<TOTAL-LIABILITY-AND-EQUITY>                  $842,146
<SALES>                                       $198,394
<TOTAL-REVENUES>                              $198,394
<CGS>                                         $132,032
<TOTAL-COSTS>                                 $166,028
<OTHER-EXPENSES>                                    $0
<LOSS-PROVISION>                                    $0
<INTEREST-EXPENSE>                                $197
<INCOME-PRETAX>                                $32,231
<INCOME-TAX>                                   $12,054
<INCOME-CONTINUING>                            $20,177
<DISCONTINUED>                                      $0
<EXTRAORDINARY>                                     $0
<CHANGES>                                           $0
<NET-INCOME>                                   $20,177
<EPS-PRIMARY>                                    $0.36
<EPS-DILUTED>                                    $0.36