Chapter XLVII: Section 9: And be it further enacted, That, upon affidavit

made by the claimant of such fugitive, his agent or attorney,
after such certificate has been issued, that he has reason to
apprehend that such fugitive will be rescued by force from his
or their possession before he can be taken beyond the limits
of the State in which the arrest is made, it shall be the duty
of the officer making the arrest to retain such fugitive in
his custody, and to remove him to the State whence he fled,
and there to deliver him to said claimant, his agent, or
attorney. And to this end, the officer aforesaid is hereby
authorized and required to employ so many persons as he may
deem necessary to overcome such force, and to retain them in
his service so long as circumstances may require. The said
officer and his assistants, while so employed, to receive the
same compensation, and to be allowed the same expenses, as are
now allowed by law for transportation of criminals, to be
certified by the judge of the district within which the arrest
is made, and paid out of the treasury of the United States.