SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934
                                (Amendment No. 1)

                             National Oilwell, Inc.
              -----------------------------------------------------
                                (Name of Issuer)

                                  Common Stock
              -----------------------------------------------------
                         (Title of Class of Securities)

                                    637071101
              -----------------------------------------------------
                                 (CUSIP Number)

Check the following box if a fee is being paid with this statement
[ ]. (A fee is not required only if the filing person: (1) has a previous
statement on file reporting beneficial ownership of, more than five percent of
the class of, securities described in Item 1; and (2) has filed no amendment
subsequent thereto reporting beneficial ownership of five percent or less of
such class.) (See Rule 13d-7.)

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

 The information required in the remainder of this cover page shall not be
deemed to be "filed" for the purpose of Section 18 of the Securities Exchange
Act of 1934 ("Act") or otherwise subject to the liabilities of that section of
the Act but shall be subject to all other provisions of the Act (however, see
the Notes).



CUSIP No.                            Schedule 13G
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   1   NAME OF REPORTING PERSON AND SS OR IRS IDENTIFICATION NO. OF PERSON

       Fred Alger Management, Inc.      13-2510833
       Fred M. Alger III                378-40-9572

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   2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                             (a)  [  ]
                                                             (b)  [  ]

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   3   SEC USE ONLY

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   4   CITIZENSHIP OR PLACE OF ORGANIZATION

       New York, New York

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                  5    SOLE VOTING POWER
     SHARES              172,679,000
  BENEFICIALLY    --------------------------------------------------------------
    OWNED BY      6    SHARED VOTING POWER
      EACH               -0-
   REPORTING      --------------------------------------------------------------
     PERSON       7    SOLE DISPOSITIVE POWER
      WITH               172,679,000
                  --------------------------------------------------------------
                  8    SHARED DISPOSITIVE POWER
                         -0-

--------------------------------------------------------------------------------
   9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                         172,679,000

--------------------------------------------------------------------------------
  10   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*



--------------------------------------------------------------------------------
  11   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

                         1.94%

--------------------------------------------------------------------------------

 12   TYPE OF REPORTING PERSON*

        Fred Alger Management, Inc.     IA
        Fred M. Alger III               HC

--------------------------------------------------------------------------------



                                  SCHEDULE 13G

ITEM 1(A).  NAME OF ISSUER:
            Castle Convertible Fund Inc.

ITEM 1(B).  ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:
            10000 Richmond Ave
            Houston, TX 77042-4200

ITEM 2(A).  NAME OF PERSON FILING:
            1. Fred Alger Management, Inc.
            2. Fred M. Alger III

ITEM 2(B).  ADDRESS OF PRINCIPAL BUSINESS OFFICE, OR IF NONE, RESIDENCE:
            1. 111 Fifth Avenue, New York, NY 10003 
            2. 111 Fifth Avenue, New York, NY 10003

ITEM 2(C).  CITIZENSHIP:
            1. New York
            2. St. Kitts

ITEM 2(D).  TITLE OF CLASS OF SECURITIES:
            Common Stock

ITEM 2(E).  CUSIP NUMBER:
            637071101

ITEM 3.     THE PERSON FILING IS A: Investment Distributor and Investment 
                                    Distributor Control Person.



                                 SCHEDULE 13G

ITEM 4(A).  AMOUNT BENEFICIALLY OWNED:
               172,679,000

ITEM 4(B).  PERCENT OF CLASS:
                1.94%

ITEM 4(C).  NUMBER OF SHARES AS TO WHICH SUCH PERSON HAS:

               (1)   sole power to vote or to direct the vote 
                      172,679,000

               (ii)  shared power to vote or to direct the vote 
                      -0-

               (iii) sole power to dispose or to direct the disposition of
                     172,679,000

               (iv)  shared power to dispose or to direct the disposition of 
                      -0-

ITEM 5.     OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS.

            If this statement is being filed to report the fact that as of the
            date hereof the reporting person has ceased to be the beneficial
            owner of more than five percent of the class of securities, check
            the following [ X ].

ITEM 6.     OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER
            PERSON.

               n/a

ITEM 7.     IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED
            THE SECURITIES BEING REPORTED ON BY THE PARENT HOLDING COMPANY.

               n/a

ITEM 8.     IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP:
               Fred Alger Management, Inc.        IA
               Fred M. Alger III                  HC

ITEM 9.     NOTICE OF DISSOLUTION OF GROUP.



ITEM 10.    CERTIFICATION.

                 By signing below I certify that, to the best of my knowledge
and belief, the securities referred to above were acquired in the ordinary
course of business and were not acquired for the purpose of, and do not have the
effect of, changing or influencing the control of the issuer of such securities
and were not acquired in connection with or as a participant in any transaction
having such purposes or effect.

                 After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this statement is true,
complete and correct.

                                             Fred Alger Management, Inc.

                                             By:
                                              ----------------------------------
                                              Hal Liebes
                                              Executive Vice President
                                              August 10, 2005



                                             Fred M. Alger III

                                             By:
                                              ----------------------------------
                                              Frederick A. Blum
                                              Attorney-in-fact
                                              August 10, 2005