If no time for acceptance is stipulated in the offerer's letter, the acceptor has a reasonable time in which to accept. What is a reasonable time, depends upon the nature of the transaction, and the circumstances surrounding it. If the offeror stipulates in his letter that the offer must be accepted by any stipulated time, the offer, of itself, lapses at the expiration of that time. If A mails a letter to B, offering to sell one hundred bushels of wheat for one hundred dollars ($100.00), and the following day B mails a letter, properly addressed, postage prepaid, to A, accepting the offer, and the letter is lost, the contract is complete and B may recover from A thereon.
If A, by letter offers to sell B one hundred bushels of wheat for one hundred dollars ($100.00), the offer to remain open until Thursday, and B mails his letter of acceptance Wednesday, and the letter is lost, the contract is binding and A is liable thereon. If A by letter offers to sell B one hundred bushels of wheat for one hundred dollars ($100.00), the offer to be accepted upon receipt of B's reply, and B's reply is lost in the mails, there is no contract.
20. Revocation. It is a well recognized principle of contracts that an offer may be revoked, or withdrawn, at any time before acceptance. In case of revocation by mail, however, the letter of revocation must be received by the acceptor, before he has mailed his letter of acceptance. For example, A mails B a letter offering to sell B one hundred bushels of wheat for one hundred dollars ($100.00). B mails his letter of acceptance. By the next mail B receives a letter of revocation. The contract is valid since the letter of revocation was not received, until after the letter of acceptance was mailed.
The only offers that cannot be withdrawn at any time before acceptance, are what are known in law as options. Options are contracts to keep an offer open for a stipulated length of time. They require a consideration, an agreement and all the elements of an ordinary contract. They are contracts. A agrees by letter to sell B one hundred bushels of wheat, and to keep the offer open three days. On the second day, and before B has mailed his acceptance, B receives a letter from A, by which A withdraws his offer. B cannot now accept A's offer, since there was no consideration for A's promise to keep the offer open three days.
A writes B, offering to sell him one hundred bushels of wheat for one hundred dollars ($100.00), and to keep the offer open for ten days. B writes A that he will give him $2.00 if he will keep the offer open ten days. A accepts the offer. On the sixth day B receives a letter from A revoking the offer to sell, and on the following day B mails his letter of acceptance. There is a valid contract in this case, since B had a contract with A based on a valuable consideration to keep the offer open ten days.
Contracts by telegraph are analogous in principle to contracts by letter. An offer by telegraph impliedly authorizes the receiver to accept by telegraph and the offer is accepted when the reply message is deposited with the operator. If lost, or not sent, the contract is not affected in the least.
21. Contracts under Seal. Formerly, at common law, contracts under seal were frequent. At the present time few contracts are made under seal. Originally a seal was an impression made in wax placed on a written document. Sealed instruments differ from other written instruments in that they import a consideration. At common law, no consideration need be proven to a sealed instrument. Formerly, private seals were in common use. Later, a scroll made with the pen or a line or any mark designated as a seal was sufficient.
Private seals have been abolished by statute in many of the states, so that their use is now limited. The modern tendency is not to use sealed instruments, or when used, to regard them as different in no respect from other contracts.