SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C.  20549

                                 SCHEDULE 13G

                   Under the Securities Exchange Act of 1934


                             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).

                      (Continued in the following page(s))

                               Page 1 of 5 Pages



CUSIP No.                            Schedule 13G              Page 2 of 5 Pages

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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)  [  ]

--------------------------------------------------------------------------------
   3   SEC USE ONLY




--------------------------------------------------------------------------------
   4   CITIZENSHIP OR PLACE OF ORGANIZATION

       New York, New York


--------------------------------------------------------------------------------
                  5    SOLE VOTING POWER
     SHARES              4,818,131
  BENEFICIALLY    --------------------------------------------------------------
    OWNED BY      6    SHARED VOTING POWER
      EACH               -0-
   REPORTING      --------------------------------------------------------------
     PERSON       7    SOLE DISPOSITIVE POWER
      WITH               4,818,131
                  --------------------------------------------------------------
                  8    SHARED DISPOSITIVE POWER
                         -0-

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

                         4,818,131

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



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

                         5.61%

--------------------------------------------------------------------------------
  12   TYPE OF REPORTING PERSON*

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

--------------------------------------------------------------------------------
                     *SEE INSTRUCTION BEFORE FILLING OUT!


                                  SCHEDULE 13G                 Page 3 of 5 Pages

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:





                                 SCHEDULE 13G                  Page 4 of 5 Pages

ITEM 4(A).  AMOUNT BENEFICIALLY OWNED:
               4,818,131

ITEM 4(B).  PERCENT OF CLASS:
               5.61%

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

               (1)  sole power to vote or to direct the vote
                     4,818,131

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

               (iii) sole power to dispose or to direct the disposition of
                     4,818,131

               (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 [  ].

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

                                     SCHEDULE 13G              Page 5 of 5 Pages


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.

                                             By: /s/ Frederick A. Blum
                                                 -------------------------------
                                                 Frederick A. Blum,
                                                 Executive Vice President
                                                 
                                             DATE: February 11, 2005
                                                 
                                                 

                                             By: /s/ Frederick A. Blum
                                                 -------------------------------
                                                 Frederick A. Blum,
                                                 Attorney-in-Fact
                                                 
                                             DATE: February 11, 2005