SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934
                                (Amendment No. 2)

                             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 - -------------------------------------------------------------------------------- 1 NAME OF REPORTING PERSON AND SS OR IRS IDENTIFICATION NO. OF PERSON Fred Alger Management, Inc. 13-2510833 Fred M. Alger III ###-##-#### - -------------------------------------------------------------------------------- 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 3,345,000 BENEFICIALLY -------------------------------------------------------------- OWNED BY 6 SHARED VOTING POWER EACH -0- REPORTING -------------------------------------------------------------- PERSON 7 SOLE DISPOSITIVE POWER WITH 3,345,000 -------------------------------------------------------------- 8 SHARED DISPOSITIVE POWER -0- - -------------------------------------------------------------------------------- 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 3,345,000 - -------------------------------------------------------------------------------- 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: 3,345,000 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 3,345,000 (ii) shared power to vote or to direct the vote -0- (iii) sole power to dispose or to direct the disposition of 3,345,000 (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