EXHIBIT 24.10 POWER OF ATTORNEY The undersigned, as a director of Public Service Company of Oklahoma (the "Company"), hereby makes, constitutes and appoints T. D. Churchwell and R. Russell Davis, and each of them severally, his true and lawful attorneys-in-fact and agents, each with full power and authority (acting alone and without the others) to execute in the name and on behalf of the undersigned, in any and all capacities, the Company's Annual Report on Form 10-K for 1997 and any and all amendments thereto, to be filed under the Securities Exchange Act of 1934, as amended, and any other documents and instruments incidental thereto, and to file the same, with all exhibits thereto and all documents in connection therewith, with the Securities and Exchange Commission, hereby granting to such attorneys-in-fact, and agents, and each of them, full power and authority of substitution and revocation in the premises and full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully for all intents and purposes as the undersigned might or could do in person and hereby ratifying and confirming all that such attorneys-in-fact and agents, or any of them, may do or cause to be done by virtue of this Power of Attorney. IN WITNESS WHEREOF, I have hereunto executed this Power of Attorney this 28th day of January, 1998. E. R. Brooks Director Subscribed and sworn to before me this 28th day of January, 1998 by E. R. Brooks. Judy A. Hall Notary Public My Commission Expires: July 20, 1999 EXHIBIT 24.10 POWER OF ATTORNEY The undersigned, as a director of Public Service Company of Oklahoma (the "Company"), hereby makes, constitutes and appoints T. D. Churchwell and R. Russell Davis, and each of them severally, his true and lawful attorneys-in-fact and agents, each with full power and authority (acting alone and without the others) to execute in the name and on behalf of the undersigned, in any and all capacities, the Company's Annual Report on Form 10-K for 1997 and any and all amendments thereto, to be filed under the Securities Exchange Act of 1934, as amended, and any other documents and instruments incidental thereto, and to file the same, with all exhibits thereto and all documents in connection therewith, with the Securities and Exchange Commission, hereby granting to such attorneys-in-fact, and agents, and each of them, full power and authority of substitution and revocation in the premises and full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully for all intents and purposes as the undersigned might or could do in person and hereby ratifying and confirming all that such attorneys-in-fact and agents, or any of them, may do or cause to be done by virtue of this Power of Attorney. IN WITNESS WHEREOF, I have hereunto executed this Power of Attorney this 28th day of January, 1998. Harry A. Clarke Director Subscribed and sworn to before me this 28th day of January, 1998 by Harry A. Clarke. Lina P. Holm Notary Public My Commission Expires: January 29, 1999 EXHIBIT 24.10 POWER OF ATTORNEY The undersigned, as a director of Public Service Company of Oklahoma (the "Company"), hereby makes, constitutes and appoints T. D. Churchwell and R. Russell Davis, and each of them severally, his true and lawful attorneys-in-fact and agents, each with full power and authority (acting alone and without the others) to execute in the name and on behalf of the undersigned, in any and all capacities, the Company's Annual Report on Form 10-K for 1997 and any and all amendments thereto, to be filed under the Securities Exchange Act of 1934, as amended, and any other documents and instruments incidental thereto, and to file the same, with all exhibits thereto and all documents in connection therewith, with the Securities and Exchange Commission, hereby granting to such attorneys-in-fact, and agents, and each of them, full power and authority of substitution and revocation in the premises and full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully for all intents and purposes as the undersigned might or could do in person and hereby ratifying and confirming all that such attorneys-in-fact and agents, or any of them, may do or cause to be done by virtue of this Power of Attorney. IN WITNESS WHEREOF, I have hereunto executed this Power of Attorney this 28th day of January, 1998. Glenn Files Director Subscribed and sworn to before me this 28th day of January, 1998 by Glenn Files. Lina P. Holm Notary Public My Commission Expires: January 29, 1999 EXHIBIT 24.10 POWER OF ATTORNEY The undersigned, as a director of Public Service Company of Oklahoma (the "Company"), hereby makes, constitutes and appoints T. D. Churchwell and R. Russell Davis, and each of them severally, his true and lawful attorneys-in-fact and agents, each with full power and authority (acting alone and without the others) to execute in the name and on behalf of the undersigned, in any and all capacities, the Company's Annual Report on Form 10-K for 1997 and any and all amendments thereto, to be filed under the Securities Exchange Act of 1934, as amended, and any other documents and instruments incidental thereto, and to file the same, with all exhibits thereto and all documents in connection therewith, with the Securities and Exchange Commission, hereby granting to such attorneys-in-fact, and agents, and each of them, full power and authority of substitution and revocation in the premises and full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully for all intents and purposes as the undersigned might or could do in person and hereby ratifying and confirming all that such attorneys-in-fact and agents, or any of them, may do or cause to be done by virtue of this Power of Attorney. IN WITNESS WHEREOF, I have hereunto executed this Power of Attorney this 28th day of January, 1998. Paul K. Lackey, Jr. Director Subscribed and sworn to before me this 28th day of January, 1998 by Paul K. Lackey, Jr. Lina P. Holm Notary Public My Commission Expires: January 29, 1999 EXHIBIT 24.10 POWER OF ATTORNEY The undersigned, as a director of Public Service Company of Oklahoma (the "Company"), hereby makes, constitutes and appoints T. D. Churchwell and R. Russell Davis, and each of them severally, her true and lawful attorneys-in-fact and agents, each with full power and authority (acting alone and without the others) to execute in the name and on behalf of the undersigned, in any and all capacities, the Company's Annual Report on Form 10-K for 1997 and any and all amendments thereto, to be filed under the Securities Exchange Act of 1934, as amended, and any other documents and instruments incidental thereto, and to file the same, with all exhibits thereto and all documents in connection therewith, with the Securities and Exchange Commission, hereby granting to such attorneys-in-fact, and agents, and each of them, full power and authority of substitution and revocation in the premises and full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully for all intents and purposes as the undersigned might or could do in person and hereby ratifying and confirming all that such attorneys-in-fact and agents, or any of them, may do or cause to be done by virtue of this Power of Attorney. IN WITNESS WHEREOF, I have hereunto executed this Power of Attorney this 28th day of January, 1998. Paula Marshall-Chapman Director Subscribed and sworn to before me this 28th day of January, 1998 by Paula Marshall-Chapman. Barbara Masterson Notary Public My Commission Expires: March 8, 1998 EXHIBIT 24.10 POWER OF ATTORNEY The undersigned, as a director of Public Service Company of Oklahoma (the "Company"), hereby makes, constitutes and appoints T. D. Churchwell and R. Russell Davis, and each of them severally, his true and lawful attorneys-in-fact and agents, each with full power and authority (acting alone and without the others) to execute in the name and on behalf of the undersigned, in any and all capacities, the Company's Annual Report on Form 10-K for 1997 and any and all amendments thereto, to be filed under the Securities Exchange Act of 1934, as amended, and any other documents and instruments incidental thereto, and to file the same, with all exhibits thereto and all documents in connection therewith, with the Securities and Exchange Commission, hereby granting to such attorneys-in-fact, and agents, and each of them, full power and authority of substitution and revocation in the premises and full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully for all intents and purposes as the undersigned might or could do in person and hereby ratifying and confirming all that such attorneys-in-fact and agents, or any of them, may do or cause to be done by virtue of this Power of Attorney. IN WITNESS WHEREOF, I have hereunto executed this Power of Attorney this 28th day of January, 1998. William R. McKamey General Manager and Director Subscribed and sworn to before me this 28th day of January, 1998 by William R. McKamey. Lina P. Holm Notary Public My Commission Expires: January 29, 1999 EXHIBIT 24.10 POWER OF ATTORNEY The undersigned, as a director of Public Service Company of Oklahoma (the "Company"), hereby makes, constitutes and appoints T. D. Churchwell and R. Russell Davis, and each of them severally, his true and lawful attorneys-in-fact and agents, each with full power and authority (acting alone and without the others) to execute in the name and on behalf of the undersigned, in any and all capacities, the Company's Annual Report on Form 10-K for 1997 and any and all amendments thereto, to be filed under the Securities Exchange Act of 1934, as amended, and any other documents and instruments incidental thereto, and to file the same, with all exhibits thereto and all documents in connection therewith, with the Securities and Exchange Commission, hereby granting to such attorneys-in-fact, and agents, and each of them, full power and authority of substitution and revocation in the premises and full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully for all intents and purposes as the undersigned might or could do in person and hereby ratifying and confirming all that such attorneys-in-fact and agents, or any of them, may do or cause to be done by virtue of this Power of Attorney. IN WITNESS WHEREOF, I have hereunto executed this Power of Attorney this 28th day of January, 1998. Robert B. Taylor, Jr. Director Subscribed and sworn to before me this 28th day of January, 1998 by Robert B. Taylor, Jr. Lina P. Holm Notary Public My Commission Expires: January 29, 1999