<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 ON FORM 10-Q.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1998
<PERIOD-END>                               JUN-30-1998
<CASH>                                         $43,091
<SECURITIES>                                        $0
<RECEIVABLES>                                 $135,111
<ALLOWANCES>                                    $2,612
<INVENTORY>                                   $109,307
<CURRENT-ASSETS>                              $303,124
<PP&E>                                      $1,214,345
<DEPRECIATION>                                $718,417
<TOTAL-ASSETS>                                $899,701
<CURRENT-LIABILITIES>                         $119,643
<BONDS>                                             $0
<PREFERRED-MANDATORY>                               $0
<PREFERRED>                                         $0
<COMMON>                                          $528
<OTHER-SE>                                    $524,592
<TOTAL-LIABILITY-AND-EQUITY>                  $899,701
<SALES>                                       $419,252
<TOTAL-REVENUES>                              $419,252
<CGS>                                         $285,253
<TOTAL-COSTS>                                 $352,860
<OTHER-EXPENSES>                                    $0
<LOSS-PROVISION>                                    $0
<INTEREST-EXPENSE>                              $1,707
<INCOME-PRETAX>                                $65,867
<INCOME-TAX>                                   $21,407
<INCOME-CONTINUING>                            $44,460
<DISCONTINUED>                                      $0
<EXTRAORDINARY>                                     $0
<CHANGES>                                           $0
<NET-INCOME>                                   $44,460
<EPS-PRIMARY>                                    $0.83
<EPS-DILUTED>                                    $0.83