(2) The offer of an act for a promise. If a farmer offers to haul a broken automobile to the repair shop for five dollars, he offers an act-the hauling-for a promise of being paid a certain sum of money. Other common illustrations are seen where one enters a street car and thus accepts the offered act of the street car company to transport him in return for his promise to pay the fare. Or where one does work for another who has knowledge that pay is expected for the same, the work is an offer and the receiving of the work without dissent,1o is an acceptance and promise to pay. (3) The offer of a promise for an act. Where a man offers a reward of five dollars to any one who will return lost property, he offers a promise for an act, and is bound by his promise to one who returns the property. The nature of the offer and acceptance are the same where one orders a bill of goods from his merchant, who accepts the offer of a promise to pay for the goods by his act of selling and delivering them to the one who has ordered.

(4) The offer of a promise for a promise. This is illustrated where one offers to pay another a certain sum on a certain day, in return for the latter's promise to perform certain services or to deliver him a certain article on or before that day. There is a binding contract as soon as the promise offered is accepted by the counter promise desired.

In the second and third situations, something remains to be done by only one of the parties after the contract has come into existence; while in the fourth situation, both parties have something to do before the contract is fulfilled. In the second and third cases, the contract is called "executory" only on the side of the party who made the promise, while in the fourth case it is "executory" as to both parties.

Contracts of the first class are called contracts "under seal"; those of the second and third classes "unilateral" 10 Day v. Caton, 119 Mass. 513, 20 Am. Rep. 347.

contracts; and those of the fourth class "bilateral" contracts.

§ 8. Communication of Offer. It is plain that there can be no meeting of the minds or agreement unless the offer is communicated to one whose acceptance is desired. One cannot accept an offer of which he has no knowledge, even by doing the act for which the offer was made. This principle has found application in cases where one has performed services for another person without the knowledge of such person, who was thus unable to accept or refuse the services. Thus, where a farmer, seeing his neighbor's stack of grain in danger of fire, moved it to a place of safety without the knowledge of the owner, it was held that he could not recover for the services.11 Similar cases are where a reward has been offered for the performance of a certain act, such as the apprehension of one who has committed a crime, and such apprehension is secured by one acting in ignorance of the offer.12 In these cases it is held that there can be no recovery.

In accordance with this principle, one accepting an apparently complete offer, will not be bound by terms intended by the offeror to be included in the offer, but of which the offeree did not have knowledge. Illustrations of this arise where railway and express companies issue tickets, receipts, bills of lading or other documents containing terms printed in fine print and modifying the liability of the carrier. The question in such cases is whether the acceptor has in fact read the terms of the offer stated in the fine print, or whether reasonable notice of the terms was given by what appeared on the ticket or bill of lading.13

§ 9. Necessity and Manner of Acceptance. It is a universal rule that there must be an acceptance of an offer before there can be an agreement and resulting contract. An offer may be revoked at any time before it is accepted,

11 Bartholomew v. Jackson, 20 Johns. (N. Y.) 28, 11 Am. Dec. 237.

12 Fitch v. Snedaker, 38 N. Y. 248; Williams v. West Chicago St. R. Co., 191 Ill. 610, 61 N. E. 456, 85 Am. St. Rep. 278.

18 Blossom v. Dodd, 43 N. Y. 264; Malone v. Railroad, 12 Gray (Mass.) 388, 74 Am. Dec. 598.

and the acceptance is necessary to change the offer to a promise.

Acceptance of an offer may be accomplished by words or conduct, or, in the case of offers under seal, by mere assent. Sometimes the acceptance is in the form of a promise. Thus, if one offers another a sum of money if he will promise to do something on a future day, the other accepts when he promises to do the act named. This is an express promise. Acceptance may also be in the form of an implied promise to be inferred from the conduct of the offeree, as where one sends goods to another, who uses them or deals with them as his own. In such case he will be liable on an implied promise to pay for the goods what they were worth, unless he had good reason to believe and did believe that they were a gift. Acceptance may also be by an act. This is seen where one offers to pay a sum of money or to do a certain thing upon another's performance of a certain act. Thus, an offer of five dollars reward for the return of a lost purse would be accepted and become a binding contract to pay upon the return of the purse by one knowing of the offer of the reward.

Sometimes it has been urged that conduct in keeping silence may amount to acceptance of an offer, but this can be the case only where there is a duty to speak.14 Thus, one cannot make silence constitute an acceptance by making an offer and stating that silence will be taken as an acceptance. This was clearly illustrated in a leading English case, where an uncle offered by letter to buy his nephew's horse for £30, 15s., adding, "If I hear no more about him, I consider the horse mine at £30, 15s." No answer was returned and it was held that since the nephew had never signified his acceptance of the offer, there was no contract of sale.15 Circumstances are rare where mere silence will impose a contractual obligation.

Acceptance sometimes takes the form of signing or mere acceptance of a document purporting to express the terms 14 Royal Ins. Co. v. Beatty, 119 Pa. 6, 12 Atl. 607, 4 Am. St. Rep. 622. 15 Felthouse v. Brindley, 11 C. B. (N. S.) 868.

of the contract. In the former case the acceptor will not be permitted to show that he did not know its terms, and, in the absence of fraud, will be bound by them. Whether one who accepts a paper is held to have accepted its terms, is largely a question whether the instrument is of such a nature as one would reasonably suppose would contain the terms of a contract. Thus, one would more reasonably expect a bill of lading, than a baggage check, to contain the terms of the contract of carriage.

Acceptance Must Be by Party Receiving Offer. Offers may be made to a particular person or persons or to the public generally. If made to a particular person, only that one can accept, and an attempted acceptance by some other person will not create a binding contract. Thus, where the president of a railroad had said to laborers of contractors and sub-contractors who had stopped work for fear they would not be paid, "Go back to your work and I will see that you are paid", it was held that a sub-contractor who was present and heard the offer could not recover upon it, since the offer was not made to him.16

Acceptance Must Correspond with Offer. An acceptance upon conditions not included in the offer will not create a binding contract. Thus, where A offered to sell B a horse for $100 and B answered that he would buy if A would warrant the horse to be sound, there was no contract until A had assented to the new term introduced by B. B's answer was not an acceptance, but in effect a counteroffer containing a condition. In the same way an offer to sell a specified quantity of goods cannot be made binding upon the offeror by ordering a less quantity or a greater quantity, for there is no offer to sell any quantity greater or less than that specified.17 Or if one offers to sell an article to another for a certain sum, and the latter replies that he will give a less sum, there is no contract, and the original offer cannot be accepted without its renewal by the offeror.

16 Indianapolis R'y Co. v. Miller, 71 Ill. 463.

17 Minneapolis & St. L. R'y v. Rolling Mill, 119 U. S. 149, 30 L. ed. 376.

§ 10. Time, Place, and Mode of Acceptance. Acceptance must be in the manner, within the time, and at the place expressly or impliedly stated in the offer. Thus, where A by letter offered to engage B as a milliner, and asked a reply "by return mail", an acceptance mailed four days after receipt of the letter did not create a binding contract.18 An answer by mail is insufficient if the offer requests reply by telegraph. An offer received by mail impliedly requires an answer by mail within a reasonable time, if no particular time for acceptance is specified, and an offer received by telegraph impliedly requires an answer by telegraph.

§ 11. Communication of Acceptance. Mere mental determination by the offeree to accept does not create a binding agreement. The acceptance must be evidenced by some act or promise indicated by the terms and conditions of the offer to be the proper method of acceptance. Thus, where A wrote to B, "Upon agreeing to finish the fitting up of offices, 57 Broadway, in two weeks from date, you can commence work at once", it was held that B's purchasing of material for the work and making other preparations unknown to A, constituted merely a mental determination and, therefore, not an acceptance binding on A, who had revoked the offer.19 Whether the acceptance must come to the personal knowledge of the offeror, depends upon the nature and terms of the offer. Thus, in those cases where the offer is of a promise for an act, the mere performance of the act completes the contract unless the offer prescribes communication. An order to ship goods is sufficiently accepted by the act of shipping, and at that moment the contract is accepted and becomes binding. An offer of five dollars to any one who finds and restores my watch, does not require acceptance by people coming to me and saying they intend to hold me to my offer and will try to earn the five dollars. The only acceptance necessary is the finding and restoring of the watch.

18 Maclay v. Harvey, 90 Ill. 525, 32 Am. Rep. 35.

19 White v. Corlies, 46 N. Y. 467.