The defendant next argues that the contract, whatever its terms,
was determinable at the will of either party and that it was deter-
mined by the defendant. The general rule is that stated by Lord
Selborne in Llanelly Railway and Dock Co. v. London and North-
Western Railway Co. (1): " An agreement de futuro, extending over
a tract of time which, on the face of the instrument, is indefinite
and unlimited, must (in general) throw upon anyone alleging that
it is not perpetual, the burden of proving that allegation." In the
present case the agreement does not provide in terms for any time
limit or for any right of withdrawal by either party. Prima facie,
therefore, the agreement continues in force for an indefinite period.
In the next place, the absence of a time limit is an ordinary and
almost necessary feature of agreements of this type: See Palmolive
Company (of England) Ltd. v. Freedman (2), per Lawrence U.J.,
where the learned Lord Justice mentions the practical commercial
reasons for excluding any time limit or power of withdrawal from
price-maintenance agreements. Finally, the only argument in
favour of implying a time limit is based upon the appearance of the
words "during the currency of our arrangement" in the final
paragraph of the plaintifi's offer. It is argued, on the authority of
Crediton Gas Company v. Crediton Urban District Council (3) that
these words impliedly give to each party a right to determine the
contract at any time. But in the case cited the nature of the
contract was such and the recitals and operative words were such
that there were "clear indications that it was contemplated that
the agreement should be subject to determination" (4). In the
present case there are no such recitals or operative words and the
nature of the agreement is such as to lead to an opposite implication.
The agreement would become commercially useless to both parties
if the reference to the currency of the agreement were interpreted,
contrary to the tenor of the whole contract, as enabling either party
to put an end to the contract at any moment.