EXHIBIT 12
                                                                         COMPUTATION OF RATIO OF          
                                                                        EARNINGS TO FIXED CHARGES
                                                                                 UNAUDITED

                                         Twelve Months                  Fiscal Year Ended September 30
                                             Ended             -------------------------------------------------------      
                                          March 31, 1999       1998          1997       1996       1995      1994
                                                                                           
                                        ------------------------------------------------------------------------------
                                                                         (Thousands of Dollars)

EARNINGS:


Income Before Interest Charges  and Minority   
  Interest in Foreign Subsidiaries (2)          $201,828       $118,085     $169,783    $159,599  $128,061  $127,885
Allowance for Borrowed Funds Used in 
   Construction                                      272            110          346         205       195       209
Federal Income Tax                                16,084         43,626       57,807      55,148    30,522    36,630
State Income Tax                                   5,906          6,635        7,067       7,266     4,905     6,309
Deferred Inc. Taxes - Net (3)                     41,411        (26,237)       3,800       3,907     8,452     4,853
Investment Tax Credit - Net                         (698)          (663)        (665)       (665)     (672)     (682)
Rentals (1)                                        4,269          4,672        5,328       5,640     5,422     5,730
                                                --------        -------     --------    --------  --------  --------

                                                $269,072        $146,228    $243,466    $231,100  $176,885  $180,934
                                                ========        ========    ========    ========  ========  ========

FIXED CHARGES:

Interest & Amortization of Premium and
   Discount of Funded Debt                       $63,724         $53,154     $42,131     $40,872   $40,896   $36,699
Interest on Commercial Paper and
   Short-Term Notes Payable                       17,372          13,605       8,808       7,872     6,745     5,599
Other Interest (2)                                 3,936          16,919       4,502       6,389     4,721     3,361
Rentals (1)                                        4,269           4,672       5,328       5,640     5,422     5,730
                                                 -------         -------     -------     -------   -------   -------

                                                 $89,301         $88,350     $60,769     $60,773   $57,784   $51,389
                                                 =======         =======     =======     =======   =======   =======

RATIO OF EARNINGS TO FIXED CHARGES                  3.01            1.66        4.01        3.80      3.06      3.52



Notes: 

   (1) Rentals  shown above  represent  the  portion of all rentals  (other than
       delay rentals) deemed representative of the interest factor.

   (2) Twelve months ended March 31, 1999  and, fiscal 1998,  1997, 1996, 1995
       and 1994 reflect the reclassification of $1,786,  $1,716, $1,716, $1,716,
       $1,716 and $1,674, representing  the loss on reacquired debt amortized
       during each period, from Other Interest Charges to Operation Expense.

   (3) Deferred  Income  Taxes - Net for fiscal  1998 and 1994 exclude the
       cumulative effect of changes in accounting.