
51 U.S. 419 (____)
10 How. 419
THE WASHINGTON, ALEXANDRIA, AND GEORGETOWN STEAM PACKET COMPANY, PLAINTIFFS IN ERROR,
v.
FREDERICK E. SICKLES AND TRUMAN COOK.
Supreme Court of United States.

*429 It was argued by Mr. Lawrence, for the plaintiffs in error, and by Mr. Lee and Mr. Bradley, for the defendants in error.
*437 Mr. Justice GRIER delivered the opinion of the court.
Sickles and Cook, plaintiffs below, filed their declaration in assumpsit, containing two counts.
The first sets forth a parol contract made with William Gunton, president of the steamboat company and general agent thereof, in which it was agreed that the plaintiffs should construct and place on board the steamboat Columbia a certain machine invented by Sickles, called a "cut-off," at their own cost; that the machine should be tried, and, if it was found to produce any saving of fuel, that the cost of putting it in operation, not exceeding two hundred and fifty dollars, should be first paid out of the savings of fuel effected by the machine; that the machine should be used by the defendants during the continuance of the patent, if the boat should last so long; and after paying for its erection, the savings caused thereby in the consumption of fuel should be divided between the plaintiffs and defendants in the proportion of one fourth to defendants and three fourths to plaintiffs. The mode of ascertaining the amount of saving is specially set forth,  and the plaintiffs aver that they erected their cut-off on said steamboat at the *438 cost of $242, on the 9th of November, 1844, and that it was afterwards ascertained in the mode agreed upon, that the saving of fuel caused by using plaintiffs' cut-off exceeded that of the "throttle cut-off," before used by defendants, by 34 175/190 per cent.; and that the amount saved over and above the price of erection when this suit was brought was $ 2,500. For the amount of the $ 242, and three fourths of the latter sum, this suit is brought.
There is a second count, for putting the machine on the boat at request of defendants, with a quantum meruit.
On the trial of the cause below, evidence was given tending to prove the special contract as laid in the first count, and that the experiment to test the value had been made in the manner agreed upon, with the result as stated in the declaration. The plaintiffs then offered to show experiments made by practical engineers on other boats, and the result thereof, with the opinion of the said engineers as to the value of their cut-off. This evidence was objected to, and its admission is the subject of the first bill of exceptions, sealed at request of defendants.
The objection to this evidence is, that the mode of ascertaining the value of plaintiffs' cut-off is specially stated in the declaration, and no other could be resorted to. But we think that, even if there were no other count in the declaration than that on the special contract, this objection cannot be sustained. The plaintiffs had given in evidence the experiment made in pursuance of their alleged agreement, and as this testimony tended only to corroborate it, and not to contradict it, or enlarge the claim of the plaintiffs beyond that ascertained by the experiment made by the parties, it cannot be said to be irrelevant or incompetent; at most, it could only be said to be superfluous. But assuming that it was irrelevant on the first count, it is clearly not so as regards the common count on a quantum meruit. The plaintiffs had an undoubted right to give evidence which might enable them to recover on the latter count, in case the defendants should succeed in establishing their plea of non-assumpsit as to the first. In this view of the case, the competency and relevancy of the testimony cannot be doubted.
To support the issue on their part, the defendants then called William Gunton, the late president of the company, who wholly denied that he made such a contract as that declared on by plaintiffs, and stated that plaintiffs expressed to him a desire to bring their "cut-off" to the favorable notice of the government, with a view of introducing it on board the national steamships. That he gave them leave to erect their machine on the boat at their own expense, and agreed that, if, on trial, the machine should be approved by the defendants, they would *439 purchase it, on terms to be afterwards agreed upon; but if not approved, or the terms of purchase offered by plaintiffs should be such as defendants would not accept, then plaintiffs should have leave to take off their machine at their own expense. That afterwards, when the plaintiffs' terms were asked, they said defendants should have the machine on the same terms as the steamboat Augusta and other boats, but would not then or at any other time state definitely what those terms were, or what price the Augusta had given, or the plaintiffs would be willing to take, so that it could be laid before the company for their approval. That defendants had never refused permission to plaintiffs to take away the machine from the boat, if they so desired to do. Certain letters were also given in evidence, the contents of which it is not necessary to state in order to understand the instructions given to the jury which are now the subject of exception.
Four several bills of exception have been taken to the refusal of the court to give four items of instruction to the jury. Two of these only are relied on here. The first may be briefly stated thus:  That if the jury believed the testimony of William Gunton, and that the contract between the parties was such as he stated, defendants were entitled to a verdict. This instruction was refused by a divided court.
We are of opinion that the defendants were clearly entitled to have this instruction given to the jury, as the testimony, if believed by them, fully supported the defendants' plea, and showed that the plaintiffs were not entitled to recover on either count in their declaration. They could not recover on the first count, for this testimony showed that there was no such contract between the parties as that set forth in it; nor on the count on a quantum meruit, for the use of the machine, for that would be a repudiation of the contract as proved. If the plaintiffs put their machine on board of defendants boat for the purpose of experiment, on an agreement that defendants should pay for it if on trial they approved it, and were willing to give the price asked, otherwise the plaintiffs should have leave to take it away,  it certainly needs no argument to show, that, without stating their terms, or offering to fulfil their contract by a sale of the machine, the plaintiffs cannot repudiate it and sue for the use of the machine. This would be a palpable fraud on the defendants.
The only other exception urged to the charge of the court below is in the answer given by the court to the fourth instruction prayed; which is as follows: 
"If, from the evidence, the jury shall find that William Gunton, the president of the defendants' company, and acting as *440 their general agent, made with the plaintiffs the contract set out in the first count of the said declaration, and that the plaintiffs, under the said contract, put the said machine on the defendants' boat, and the same was used by the defendants at the time and times mentioned in the said count, and that the same was beneficial to the defendants, then the plaintiffs are entitled to recover on the said first count, notwithstanding the jury shall find that the terms of the said contract were not communicated to the defendants, and the said William Gunton reported to the said defendants a different contract."
We find no fault with this instruction, so far as it states the liability of defendants for the acts of Gunton as their general agent, whether he reported his agreement to the defendants or not. If he was their general agent, and had power to make such contract, his failure to communicate it to his principals cannot affect the case. But we are of opinion, that the court erred in stating that the plaintiffs had a right to recover on their special count, if the machine was useful to the defendants, without regarding the stipulations of said contract as laid and proved, and the fact that the plaintiffs had refused to rescind it, and had expressed their determination to adhere to it and "to bring an action every week to recover the amount of saving on the terms of the contract."
If the plaintiffs had complied with the request of the president of the company, in a letter addressed to them on the 14th of April, 1841, after the dispute about the nature of the contract had arisen, and taken their cut-off from the boat, and thus put an end to the contract, the instructions given by the court would have been undoubtedly correct. But as the record shows that the plaintiffs have refused to annul the contract, a very important question arises,  whether this action and five hundred others, which the plaintiffs have expressed their determination to continue to institute, can be supported on this one contract. By the contract as proved and declared on, the defendants, after the machine has been erected on their boat, are to continue to use it "during the continuance of the patent," if the boat should last so long. The compensation to be paid by the defendants is to be measured by the amount of saving of fuel which the machine shall effect. The mode of ascertaining this saving is pointed out, and the ratio in which it is to be divided. The first $ 250 saved are all to go to the plaintiffs, and three fourths of all the balance. But the contract is wholly silent as to the time when any account shall be rendered or payments made. The defendants have not agreed to pay by the trip, or settle their account every day, or week, or year; or at the end of 27½ weeks, the time for which this suit is *441 instituted. The agreement on the part of the plaintiffs is, that the defendants shall use their machine for a certain time, in consideration of which defendants are to pay a certain sum of money. It is true, the exact sum is not stated; but the mode of rendering it certain is fully set forth. It is one entire contract, which cannot be divided into a thousand, as the plaintiffs imagine. If the defendants had agreed to pay by instalments at the end of every week, or twenty-seven weeks, doubtless the plaintiffs could have sustained an action for the breach of each promise, as the breaches successively occurred. But it is a well-settled principle of law, that, "unless there be some express stipulation to the contrary, whenever an entire sum is to be paid for the entire work, the performance or service is a condition precedent; being one consideration and one debt, it cannot be divided." It was error, therefore, to instruct the jury that the plaintiffs were entitled to recover on the first count, if their machine was used by the defendants, and was beneficial to them, without regard to the fact of the rescission, or continuance, or fulfilment, of the contract on the part of the plaintiffs.
Whether, if there had been a count in the declaration for the $ 242, and the jury had believed that the defendants had agreed to pay it as soon as it was earned, the plaintiffs might not recover to that amount, or whether such a construction could be put on the contract as proved, are questions not before us, and on which we therefore give no opinion.
The judgment of the Circuit Court must, therefore, be reversed.

Order.
This cause came on to be heard on the transcript of the record from the Circuit Court of the United States for the District of Columbia, holden in and for the County of Washington, and was argued by counsel. On consideration whereof, it is now here ordered and adjudged by this court, that the judgment of the said Circuit Court in this cause be, and the same is hereby, reversed, with costs, and that this cause be, and the same is hereby, remanded to the said Circuit Court, with directions to award a venire facias de novo.
