<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
QUARTERLY REPORT ON FORM 10-Q AND IS QUALIFIED IN ITS ENTIRETY BY SUCH QUARTERLY
REPORT OF FORM 10-Q.
</LEGEND>
<MULTIPLIER> 1,000

                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-END>                               JUN-30-1999
<CASH>                                         $35,874
<SECURITIES>                                        $0
<RECEIVABLES>                                 $137,097
<ALLOWANCES>                                    $2,894
<INVENTORY>                                   $124,497
<CURRENT-ASSETS>                              $310,279
<PP&E>                                      $1,272,438
<DEPRECIATION>                                $762,232
<TOTAL-ASSETS>                                $937,418
<CURRENT-LIABILITIES>                         $126,089
<BONDS>                                             $0
<PREFERRED-MANDATORY>                               $0
<PREFERRED>                                         $0
<COMMON>                                          $470
<OTHER-SE>                                    $476,007
<TOTAL-LIABILITY-AND-EQUITY>                  $937,418
<SALES>                                       $409,156
<TOTAL-REVENUES>                              $409,156
<CGS>                                         $276,327
<TOTAL-COSTS>                                 $354,960
<OTHER-EXPENSES>                                    $0
<LOSS-PROVISION>                                    $0
<INTEREST-EXPENSE>                              $5,319
<INCOME-PRETAX>                                $71,911
<INCOME-TAX>                                   $24,126
<INCOME-CONTINUING>                            $47,785
<DISCONTINUED>                                      $0
<EXTRAORDINARY>                                     $0
<CHANGES>                                           $0
<NET-INCOME>                                   $47,785
<EPS-BASIC>                                      $1.02
<EPS-DILUTED>                                    $1.00