whether under the cireumstances of the case an implied contract
to pay for them is to be inferred. That is an inference of fact to
be drawn by the tribunal which is ealled upon to determine the
matter, that is, the umpire. Now, the only fact found is that the
employer had such knowledge as to these works as may be fairly
inferred from the fact that he was constantly on the work, and
taking an active interest therein. But a further inference
must be drawn before a liability to pay arises, namely, that there
was an implied contract to pay. It might be inferred, on the
one hand, that, having regard to the nature of the works, the
fact of the owner's presence, and the nature of the interest he
took, he knew that they were outside the contract, and knew
that the contractor expected to be paid for them as extras. On
the other hand, it might be inferred as to all or some of them that
he did not know that they were extras, or did not know or
believe that the contractor expected to be paid for them. But
that as I have said is a question of fact, and the umpire, not the
Court, is the judge of the facts. It is impossible, we think, for
this Court, or for the Supreme Court to draw the necessary infer-
ence of fact. It must be drawn by the umpire himself, and upon
his finding on the question of fact depends the right of the appel-
lant to recover the amount claimed or any part of it. An implied
contract may be proved in various ways. When a man does
work for another without any express contract relating to the
matter, an implied contract arises to pay for it at its fair value.
Such an implication of course arises from an express request to
do work made under such circumstances as to exclude the idea
that the work was covered by a written contract. So it would
arise from the owner standing by and seeing the work done by
the other party, knowing that the other party, in this case the
contractor, was doing the work in the belief that he would be paid
for it as extra work. If the umpire was of opinion that any of
this work was done under such circumstances that the owner knew
or understood that the contractor was doing the work in the belief
that he would be paid for it as extra work, then the umpire might,
and probably would, infer that there was an implied promise to
pay for it. That is one instance. Again, the architect might
have been expressly authorized by the owner to order extra