The court below decides:

(1) Where a mail-transportation service has beeD rendered in a certain way for nearly twelve years under three successive contracts, the court will adopt the construction given by the parties, though in the abstract inclined to a different one.

(2) Where the Post-Office Department allows a contractor to carry the mails under successive contracts and for many years by a route which is probably a deviation from that prescribed by the contracts, the Postmaster-General can not by a retroactive construction impose flues and forfeiture upon the contractor, nor make retro- - active deductions from his pay.

(3) It must be presumed that the Post-Office Department is informed by its agents of the manner in which a mail-transportation service continuing for many years is performed.

The decision of the court below is reversed on the ground the contract was not performed; that the burden of proof was on the contractor to show knowledge by the Department of his conduct in the premises, and that knowledge of the Department is not to be presumed from reports to the Department by the local postmaster that the service had been performed.

delivered the opinion of the Supreme court, January 6, 1890.