EX-10.c

                     INTERSTATE AMENDMENT AGREEMENT


     This Agreement dated as of September 1, 1981 (the "Interstate
Amendment Agreement") between ORBA-JOHNSON TRANSSHIPMENT COMPANY, AN IOWA
PARTNERSHIP ("OJT") and INTERSTATE POWER COMPANY, a Delaware corporation
("Interstate"),

                          W I T N E S S E T H:

     WHEREAS, OJT is an Iowa partnership formed pursuant to a Second
Amended Partnership Agreement dated as of December 20, 1979 (the
"Partnership Agreement") between Johnson Bros. Transshipment Corporation
of Iowa, an Iowa corporation ("J-Sub"), which is a wholly-owned
subsidiary of Johnson Brothers Corporation, a Minnesota corporation
("Johnson Bros."), and Orba Transshipment Corporation of Iowa, an Iowa
corporation ("O-Sub"), which is a wholly-owned subsidiary of Orba
Corporation, a Delaware corporation ("Orba");

     WHEREAS, Interstate Power Company ("Interstate") designated OJT to
acquire a rail-to-barge coal transloading and storage facility located on
the right descending bank of the Mississippi River at River Mile 371,
North of Keokuk, Iowa (the "Facility") and engaged OJT and the Facility
for the receiving, storage and transshipment of coal, and OJT so acquired
and agreed to so operate, and has so operated, the Facility;

     WHEREAS, Interstate and OJT have entered into a Second Amended and
Restated Coal Transshipment Agreement, dated as of December 20, 1979,
effective October 3, 1979, which agreement was recorded on December 20,
1979 in Book 9 at page 152 in the Records of Lee County, Iowa (the
"Transshipment Agreement"), and OJT is operating the Facility upon the
terms and conditions thereof;

     WHEREAS, OJT and The Travelers Insurance Company, on its own behalf
and on behalf of a certain separate account maintained by it
(collectively, the "Lender"), entered into two Bond Agreements, dated as
of December 20, 1979 (collectively, the "1979 Agreement"), pursuant to
which the Lender loaned OJT $27,000,000 for the long-term financing of
the Facility and pursuant to which OJT issued its 10 3/8% First Mortgage
Bonds, due March 1, 1996 (the "1979 Bonds");

     WHEREAS, pursuant to a Representation Agreement dated as of December
20, 1979 between OJT and Interstate (the "Representation Agreement"),
Interstate provided OJT with certain representations, warranties and
covenants, the rights under which were assigned by OJT to the Lender for
the benefit of the holders of the 1979 Bonds;

     WHEREAS, Lender, acting on behalf of a certain separate account
maintained by it, is entering into a Bond Agreement, dated as of the date
hereof, pursuant to which the Lender will loan OJT up to $540,000 for
financing the planning and installation of certain environmental control
equipment for the Facility, and OJT will issue its 15 1/2% First Mortgage
Bonds, Series B, due July 1, 1986 (the "Series B Bonds") to the Lender as
evidence of such loan;

     WHEREAS, in order to finance additions or improvements to the
Facility, the Lender may, from time to time, make further purchases of
first mortgage bonds, to be issued in additional series by OJT, pursuant
to additional bond agreements between OJT and the Lender (the 1979
Agreement, the Series B Bond Agreement and any such additional bond
agreements, collectively referred to herein as the "Bond Agreement"; the
1979 Bonds, the Series B Bonds and any additional bonds issued pursuant
to any such additional bond agreements between OJT and the Lender,
collectively referred to herein as the "Bonds"); and

     WHEREAS, pursuant to a Security Agreement and Assignment of
Contracts, dated as of December 20, 1979, as amended as of September 1,
1981 (the "Security Agreement"), OJT has assigned to Lender all of its
right, title and interest in, to and under the Collateral (as defined in
the Security Agreement), including its rights under the Transshipment
Agreement, in order to secure the prompt and complete payment and
performance when due of all of the Obligations (as defined in the
Security Agreement); and

     WHEREAS, pursuant to the terms of an Indemnity Assignment from OJT,
Orba and Johnson Bros. to the Lender, dated as of December 20, 1979 (the
"Indemnity Assignment"), and pursuant to the terms of a Consent and 
Clarification, dated as of October 3, 1979, OJT, Orba and Johnson Bros.
assigned to the Lender for the benefit of all holders of the 1979 Bonds
all their rights under an indemnity letter (the "Indemnity Letter") dated
October 3, 1979 from Interstate to Orba and Johnson;

     WHEREAS, in order to induce the Lender to enter into the Series B 
Bond Agreement and any such additional bond agreements which may be
entered into between the Lender and OJT from time to time to finance
additions or improvements to the Facility, and in consideration of the
Lender's entering into the Series B Bond Agreement and purchasing the
Series B Bonds pursuant to the terms thereof, and in consideration of the
Lender's entering into any additional bond agreements between the Lender
and OJT to finance additions or improvements to the Facility and
purchasing any additional series of Bonds pursuant to the terms thereof,
OJT intending to be legally bound hereby has agreed to provide the Lender
with the protection and security provided by the following amendments to
the Transshipment Agreement, the Representation Agreement and the Consent
and Clarification contained herein;

     WHEREAS, in order to induce the Lender and OJT to carry out the
transactions contemplated hereby and by the Transshipment Agreement,
Interstate has been requested by OJT and the Lender to provide, and
Interstate has agreed to provide, the amendments to the various
agreements contained herein;

     WHEREAS, the Lender desires to amend the Representation Agreement,
the Transshipment Agreement and the Consent and Clarification so that the
holders of all Bonds will be entitled to all rights and benefits provided
to the holders of the 1979 Bonds under the Representation Agreement, the
Transshipment Agreement, the Security Agreement and the Indemnity
Assignment;

     NOW THEREFORE, in consideration of the premises, of the agreements
of OJT contained in the Transshipment Agreement, of the agreements of OJT
and the Lender with respect to the long-term financing of the Facility
and additions and improvements thereto and of the mutual covenants and
agreements contained herein, the parties hereto agree as follows:


SECTION 1 REPRESENTATION AGREEMENT

     1.1  The first paragraph and the "Witnesseth" clause of the
Representation Agreement are hereby amended to read as follows:

     "This REPRESENTATION AGREEMENT dated as of December 20, 1979, as
amended as of September 1, 1981, between ORBA-JOHNSON TRANSSHIPMENT
COMPANY, an Iowa partnership ("OJT") and INTERSTATE POWER COMPANY, a
Delaware corporation ("INTERSTATE"),

                          W I T N E S S E T H:

     WHEREAS, Interstate has designated OJT to acquire a rail-to-barge
coal transloading and storage facility located on the right descending
bank of the Mississippi River at River Mile 371, North of Keokuk, Iowa
(the "Facility") and has engaged OJT and the Facility for the receiving,
storage and transshipment of coal, and OJT has so acquired and agreed to
so operate the Facility;

     WHEREAS, Interstate and OJT have entered into a Second Amended and
Restated Coal Transshipment Agreement, dated as of December 20, 1979,
effective as of October 3, 1979, as further amended as of September 1,
1981 (the "Transshipment Agreement"), pursuant to which OJT will so
operate the Facility and Interstate will make certain payments to OJT
upon the terms and conditions thereof;

     WHEREAS, in order to obtain the requisite long-term financing for
the Facility, OJT entered into two Bond Agreements, dated as of December
20, 1979 (collectively, the "1979 Agreement") with The Travelers
Insurance Company, on its own behalf and on behalf of a certain separate
account maintained by it (collectively, the "Lender"), pursuant to which
the Lender loaned OJT up to $27,000,000 for the long-term financing of
the Facility and OJT issued its 10 3/8% First Mortgage Bonds (the "1979
Bonds") to the Lender as evidence of such loan;

     WHEREAS, in order to obtain the financing for the planning and
installation of certain environmental control equipment for the Facility,
OJT proposes to enter into a Bond Agreement, dated as September 1, 1981,
with the Lender, acting on behalf of a certain separate account
maintained by it (the "Series B Bond Agreement"), pursuant to which the
Lender will loan OJT up to $540,000 for financing the planning and
installation of certain environmental control equipment for the Facility
and OJT will issue its 15-1/2% First Mortgage Bonds, due July 1, 1986,
(the "Series B Bonds") as evidence of such loan;

     WHEREAS, in order to obtain additional financing for additions and
improvements to the Facility, OJT may propose, from time to time, to
enter into additional bond agreements with the Lender, pursuant to which
the Lender will loan OJT additional amounts and OJT will issue its first
mortgage bonds in additional series to the Lender as evidence of such
loans (the 1979 Agreement, the Series B Bond Agreement and any such
additional bond agreements entered into between OJT and the Lender,
collectively referred to herein as the "Bond Agreement"; the 1979 Bonds,
the Series B Bonds and any additional first mortgage bonds issued
pursuant to any such additional bond agreements, collectively referred to
herein as the "Bonds"); and

     WHEREAS, in order to induce OJT and Lender to carry out the
transactions contemplated hereby and by the Transshipment Agreement,
Interstate has been requested by OJT and Lender to provide, and
Interstate has agreed to provide, certain representations, warranties and
covenants, all on the terms and conditions contained herein;

     NOW, THEREFORE, in consideration of the premises, of the agreements
of OJT contained in the Transshipment Agreement, of the agreements of OJT
and the Lender with respect to the long-term financing of the Facility
and additions or improvements thereto and of the mutual covenants and
agreements contained herein, the parties hereto agree as follows:

     1.2  Terms Defined. The definition of "Operative Agreements" in
Section 5.1 of the Representation Agreement is hereby amended to read as
follows:

     "Operative Agreements - collectively, this Agreement, the
Transshipment Agreement, the 1979 Agreement, the Series B Bond Agreement,
any additional bond agreement entered into between OJT and the Lender to
finance additions or improvements to the Facility, and each of the
following agreements as defined in the Series B Bond Agreement, or in the
event Lender and OJT enter into any additional bond agreements to finance
additions or improvements to the Facility, as defined in the most recent
of such bond agreements then in effect:  the Lease, the  Mortgage, the
Guaranty Agreement, the Security Agreement, the Performance Guaranty
Agreements, the Indemnity Agreement, the Indemnity Assignment, the
Assignment of Option to Repurchase, the Escrow Agreement, the Amendment
Agreement, the Interstate Amendment Agreement and the Amendment to the
Mortgage and Security Agreement, as each such agreement may be amended or
supplemented from time to time."

     1.3  Additional Provisions
     
     (a)  A new Section 2.18 is hereby added to the Representation
Agreement to read as follows:

     "2.18  Financial Statements

     The consolidated balance sheet of Interstate and its Subsidiaries as
of December 31, 1980 and related statements of income, retained earnings
and changes in financial position for the fiscal year ended on such date,
accompanied by a report as therein noted, by Deloitte, Haskins & Sells,
independent certified public accountants, and the consolidated balance
sheet of Interstate and its subsidiaries as of June 30, 1981 and the
related statements of income, retained earnings and changes in financial
position for the six months ended on such date, copies of which have been
delivered to Lender, have been prepared in accordance with generally
accepted accounting principles consistently applied, and present fairly
the financial position of Interstate and its Subsidiaries as of such
dates and the results of their operations for such periods.  These
consolidated financial statements include the accounts of all
Subsidiaries of Interstate for the respective periods during which a
subsidiary relationship has existed."

     (b)  A new Section 2.19 is hereby added to the Representation
Agreement to read as follows:

     "2.19  Business and Property

     Interstate's Annual Report on Form 10-K for the fiscal year ended
December 31, 1980 filed by Interstate with the Securities and Exchange
Commission (the "Form 10-K") correctly describes the general nature of
the business and principal properties of Interstate and its
Subsidiaries."

     1.4  Representations and Warranties.  Interstate hereby warrants and
represents to OJT that the representations and warranties of Interstate
set forth in the Representation Agreement, as hereby amended, are true
and correct on and as of the date of execution and delivery of this
Agreement with the same force and effect as if such representations and
warranties had been made on and as of such date.  Interstate hereby
affirms to OJT, as of the date of execution and delivery of this
Agreement, that it has complied with all covenants and agreements of
Interstate contained in the Representation Agreement and will comply with
all such covenants and agreements in the Representation Agreement, as
hereby amended.


SECTION 2 TRANSSHIPMENT AGREEMENT

     2.1  Definition of Financial Terms.  Subsection (b) of Section 3.2
of the Transshipment Agreement is hereby amended to read as follows:

     "`Facility Financing' shall mean any long-term indebtedness incurred
by OJT to finance the construction or acquisition of the Facility,
including the planning, construction, acquisition and installation of any
modifications, additions or improvements to the Facility or Ancillary
Hardware required to meet the requirements of this Agreement, any portion
of the Ancillary Hardware and certain of the start-up expenses, and any
renewals or refinancings thereof, including any construction financings
assumed by OJT in connection with the acquisition of the Facility (the
"Construction Financing")."

     2.2  The modifications, additions or improvements to the Facility or
Ancillary Hardware (as defined in the Transshipment Agreement, as
amended) for the purpose of complying with environmental requirements and
the costs related to the planning, construction, acquisition and
installation of said modifications, additions or improvements, which are
to be financed by the sale of the Series B Bonds, do not constitute
"Reimbursable Costs" as defined in Section 3.2(g) of the Transshipment
Agreement, as amended, and, notwithstanding the provisions of Section
1.5(e) of the Transshipment Agreement, the financing of such costs will
constitute "Facility Financing" as defined in Section 3.2(b) of the
Transshipment Agreement, as amended.


SECTION 3 CONSENT AND CLARIFICATION

     3.1  The second paragraph of the introduction to the Consent and
Clarification of Interstate, dated as of December 20, 1979, is hereby
amended to read as follows:

     "Interstate hereby acknowledges notice of the assignment by OJT,
ORBA and Johnson Bros. to The Travelers Insurance Company, on its own
behalf and on behalf of a certain separate account maintained by it (said
Travelers and said separate account being herein called collectively the 
"Lender") of the right to enforce and collect directly from Interstate
all indemnities due pursuant to the Indemnity Letter to OJT, Orba or
Johnson Bros. for which OJT, Orba or Johnson Bros. would be obligated to
Lender (the "Assignment").  In order to induce Lender to carry out the
transactions contemplated by those certain Bond Agreements dated as of
December 20, 1979 (collectively, the "1979 Agreement"), that certain 
Bond Agreement dated as of September 1, 1981 (the "Series B Bond
Agreement") and any future bond agreements which may be entered into from
time to time by Lender with OJT to finance additions or improvements to
the Facility (the 1979 Agreement, the Series B Bond Agreement and any
such additional bond agreements are collectively referred to herein as
the "Bond Agreement") and thereby to enable OJT to carry out its
obligations to Interstate pursuant to the Second Amended and Restated
Coal Transshipment Agreement dated December 20, 1979, as amended and
restated effective as of October 3, 1979, and as further amended as of
September 1, 1981 (the "Transshipment Agreement"), Interstate agrees
hereby to consent to such assignment by OJT, Orba and Johnson Bros. and
to confirm Lender's direct rights under the Indemnity Letter and to
hereby clarify the scope and substance of the indemnification provided to
Lender therein."

     3.2  The first paragraph of Section 2 of the Consent and
Clarification is hereby amended as follows:

     "Interstate hereby confirms that the Indemnity Letter may and shall
be interpreted and enforced so that Lender and any of its successors,
assigns, servants and agents, including without limitation, all of the
holders, from time to time, of the Bonds (as defined in the Series B Bond
Agreement, or, in the event Lender and OJT enter into any additional bond
agreements to finance additions or improvements to the Facility, as
defined in the most recent of such bond agreements then in effect) (such
holders herein called the "Lender Indemnitees") shall each be indemnified
by Interstate under the Indemnity Letter and, pursuant thereto,
Interstate shall protect, save, keep harmless and make whole each thereof
from and against, any and all liabilities, obligations, losses, damages,
penalties, claims, actions, suits, costs, expenses and disbursements
(including, without limitation, legal fees and expenses and claims
involving strict or absolute liability in tort) of any kind and nature
whatsoever ("Claims") imposed on, incurred by or asserted against any
Indemnitee, in any way relating to or arising out of any of the
following:"


SECTION 4 OTHER AMENDMENT AGREEMENTS

     Interstate hereby consents to the terms of the Amendment Agreement,
dated as of September 1, 1981 (the "Amendment Agreement"), among OJT, O-
Sub, J-Sub, Orba, AMCA International Corporation, a Delaware corporation,
Johnson Bros., Northwestern Bank of Minneapolis, a national banking
association, the Lender and the other holders of the 1979 Bonds, and to
the terms of the Amendment to Mortgage and Security Agreement (the
"Amendment to Mortgage and Security Agreement"), dated as of September 1,
1981, between the Lender and OJT.  Interstate acknowledges receipt of
copies of the Amendment Agreement and the Amendment to Mortgage and
Security Agreement.


SECTION 5 GENERAL

     5.1  Notices.  Any notice required or permitted to be given
          hereunder shall be deemed to have been given when mailed, first
          class, postage prepaid, addressed as follows:

     (a)  if to Interstate, at 1000 Main Street, Dubuque, Iowa 52001, 
          Attn:  President; and

     (b)  if to OJT, at P.O. Box 768, River Road, Keokuk, Iowa 52632,
          with a copy to OJT c/o Orba Corporation, Attn: President,
          One Gothic Plaza, Fairfield, New Jersey 07006.

     5.2  Governing Law.  This Agreement shall be governed by and
construed in accordance with the laws of the State of Iowa.

     5.3. Survival.  All warranties, representations, and covenants made
by Interstate herein or in any certificate or other instrument delivered
by it or on its behalf under this Agreement or any of the other Operative
Agreements (as defined in the Series B Bond Agreement, or, in the event
the Lender and OJT enter into any additional bond agreements to finance
additions or improvements to the Facility, as defined in the most recent
of such bond agreements then in effect) shall be considered to have been
relied upon by OJT and Lender and shall survive the delivery of this
Agreement and the Bonds regardless of any investigation made by or on
behalf of either of them.  All statements in any such certificate or
other instrument shall constitute warranties and representations by
Interstate hereunder.

     5.4  Successors and Assigns.  This Agreement shall inure to the
benefit of, and be binding upon, the successors and assigns of each of
the parties.  The provisions of this Agreement are intended to be for the
benefit of all holders, from time to time, of the Bonds, and shall be
enforceable by any such holder, whether or not an express assignment to
such holder of rights under this Agreement has been made.

     5.5  Counterparts.  This Agreement may be executed in several
counterparts, such counterparts constituting but one and the same
agreement.

     5.6  Authorization.  The execution, delivery and performance of this
Agreement by Interstate has been duly authorized by the Executive
Committee of Interstate's Board of Directors.

     5.7  Effective Date.  This Agreement shall become effective when
counterparts are executed and delivered on behalf of the parties hereto. 
Upon such effectiveness, the amendments contained herein shall be
effective as of September 1, 1981.  The agreements amended hereby shall
remain in full force and effect, as so amended.

     IN WITNESS WHEREOF, the parties have caused this Agreement to be
executed by one of their duly authorized officers, effective as of the
date first above written.


Executed in the
presence of:

/s/  T. H. Mahoney                 INTERSTATE POWER COMPANY 

/s/  Ann M. Mongell                By  /s/  Clyde Kurlander
                                   Title:  Attorney in Fact


/s/  T. H. Mahoney                 ORBA-JOHNSON TRANSSHIPMENT COMPANY
                                   By Orba Transshipment Corporation
                                        of Iowa, a Partner

/s/  Ann M. Mongell                By  /s/  Thomas H. Peck
                                   Title:  Vice President


/s/  T. H. Mahoney                 By Johnson Bros. Transshipment
                                        Corporation of Iowa, a Partner

/s/  Ann M. Mongell                By  /s/  Walter D. Johnson
                                   Title:  Secretary



STATE OF Connecticut     )
                         )  ss
COUNTY OF Hartford       )

     On the 15 day of September, 1981, before me, the undersigned, in and
for said County and State, personally appeared Walter D. Johnson to me
personally known, who, being duly sworn, did say that he is the Secretary
of Johnson Bros. Transshipment Corporation of Iowa, one of the partners
of Orba-Johnson Transshipment Company, an Iowa partnership, that said
corporation has no seal; that said instrument was signed by him on behalf
of such corporation as a partner of such partnership by authority of the
Board of Directors of such corporation; and that the said Walter D.
Johnson in such capacity acknowledged the execution of said instrument to
be the voluntary act of said corporation as a partner of such
partnership, by it and him voluntarily executed.

                                        /s/  Ann M. Mongell
                                        Notary Public in and for
                                        said County and State



STATE OF Connecticut     )
                         )  ss
COUNTY OF Hartford       )

     On the 15 day of September, 1981, before me, the undersigned, in and
for said County and State, personally appeared Thomas H. Peck to me
personally known, who, being duly sworn, did say that he is the Vice
President of Orba Transshipment Corporation of Iowa, one of the partners
of Orba-Johnson Transshipment Company, an Iowa partnership, that said
corporation has no seal; that said instrument was signed by him on behalf
of such corporation as a partner of such partnership by authority of the
Board of Directors of such corporation; and that the said Thomas H. Peck
in such capacity acknowledged the execution of said instrument to be the
voluntary act of said corporation as a partner of such partnership, by it
and him voluntarily executed.

                                        /s/  Ann M. Mongell
                                        Notary Public in and for
                                        said County and State



STATE OF Connecticut     )
                         )  ss
COUNTY OF Hartford       )

     On the 15 day of September, 1981, before me, the undersigned, in and
for said County and State, personally appeared Clyde Kurlander, to me
personally known, who, being duly sworn, did say that he is the Attorney
in Fact of Interstate Power Company, a Delaware corporation, that the
seal affixed thereto is the seal of said corporation; that said
instrument was signed and sealed on behalf of said corporation by
authority of the Executive Committee of its Board of Directors; that the
said Clyde Kurlander as such officer acknowledged the execution of said
instrument to be the voluntary act and deed of said corporation, by it
and by him voluntarily executed.

                                        /s/  Ann M. Mongell
                                        Notary Public in and for
                                        said County and State