Myers, C. J.
*1351. 2. *133Appellant Robison was treasurer of Marion county, Indiana, and ex officio treasurer of £he city of Indianapolis, from January 1, 1908, to January 1, 1910. Appellant Share was in the employ of said treasurer. When the latter went into office there was a card index system in the office which furnished a partial index to the assessment rolls for public improvements in the city of Indianapolis. There are some forty-threg volumes of public improvement assessments, involving more than ten thousand names of different persons and assessments. The card index in use prior to January 1, 1908, so far as the mechanical features of it were concerned, was the ordinary form of cards, adjusted to a case, with rods to hold the cards in position, and each card had the name of a person at the top thereof, and under the name, vertical ruled spaces for indicating the property assessed, and the folio and page in which the assessment was to be found, and a like space for designating the improvement! These were arranged in alphabetical order in the cases. There was an index to the improvement in each folio, and a general index to all folios, of the improvements, but the names of property owners were not indexed. There is no express statute requiring the keeping of any index of any kind. The only other reference to assessments against any property for public improvements was upon the general tax duplicates, where, opposite any parcel of land, against which there was such assessment, a letter B was placed to indicate that there was a so-called Barrett law assessment against the property, and in case a property owner should not know upon what improvement an assessment had been made, there was no way of discovering it, without *134running through the general index, or the indexes in the various folios. Appellant Share had had long experience in the conduct of the treasurer’s office, and especially with the collection of municipal assessments, and, at the suggestion, and under the pay of appellant Robison, set about devising a card index system to public improvement records. Appellant Robison personally visited a number of the larger cities of the country, examined the methods employed in keeping trace of public improvement assessments, and directed Share to work out a system of card indexes, and procured, at his personal expense, the cases and cards. Share thereupon devised a card system in which, under the name of one owner, all improvements assessed in that name appear. The only practical difference between the two systems of cards was that in the one employed when Robison came into office, but one improvement appeared upon a single card, though the cards were arranged for separate improvements, while in the system devised by Share, all improvements assessed under the name of any one person or owner were designed to be shown by such card. Robison directed Share to obtain the necessary cards and cases to install the system in the treasurer’s office, and, in the absence of the treasurer and without his knowledge, payment for the supplies was made out of the public funds. As soon as Robison discovered this fact, he covered the money into the treasury. The card system which was in vogue when Robison took office was not thereafter kept up, but the system devised by Share was completed at an expense of about $3,000 to Robison, and proved to be a great success in expediting the work of referring to assessments, and highly essential, if not indispensable, to the conduct of the office. Share applied for letters patent upon the device, and claims to be the owner of the system, while Robison claims to own the particurlar cards and the cases in which they are contained. Upon going out of office January 1, 1910, Robison claimed the cases and cards as his individual property, and the right to *135remove them, and appellee, as treasurer-elect and resident taxpayer, successfully maintained an application for an injunction against their removal, on the ground that they were parts of the public records, from which judgment both defendants appeal, and assign joint and separate errors upon the action of the court below in overruling their motions for a new trial. Jurisdiction is lodged in this court by the contention of appellants that the judgment is in violation of the 14th amendment to the federal Constitution, in abridging the privileges or immunities of citizens of the United States, and depriving them of their property without due process of law, and in violation of article 1, §21, of the state Constitution, in taking their services and property without just compensation first assessed and tendered. As to the first proposition, it is to be said that the privileges and immunities clause of the federal Constitution refers to the privileges and immunities arising out of the nature and character of the federal government, granted^ or secured by that Constitution. It operates upon state action solely, and not upon individual action, and simply requires that all persons similarly situated be treated alike, in privileges conferred or liabilities imposed. Hodges v. United States (1905), 203 U. S. 1, 27 Sup. Ct. 6, 51 L. Ed. 65; Field v. Barber Asphalt Paving Co. (1904), 194 U. S. 618, 24 Sup. Ct. 784, 48 L. Ed. 1142; Duncan v. Missouri (1894), 152 U. S. 477, 14 Sup. Ct. 570, 38 L. Ed. 485.
3. Appellants contend that the device is patentable, that a patent right is property, and that the judgment constitutes a taking without due process or just compensation. Whether it is patentable or not is immaterial, for there is some value in the cases and cards.. While the state courts have no jurisdiction to determine rights under an alleged patent, they are not ousted of jurisdiction by the fact that rights claimed or denied as growing out of the patent arc incidentally involved. Exclusive federal jurisdiction applies only to cases arising *136under the patent laws upon a bill, complaint, or declaration of a plaintiff setting up a right under the patent laws as a ground of recovery. Pratt v. Paris, etc., Coke Co. (1897), 168 U. S. 265, 18 Sup. Ct. 62, 42 L. Ed. 458 and notes; Riverside Mills v. Atlantic, etc., R. Co. (1909), 168 Fed. 987; Osborn v. President, etc. (1824), 9 Wheat. *738, 6 L. Ed. 204; Pittsburgh, etc., R. Co. v. Mitchell (1911), post, 196.
4. The real point in this case turns on the question whether the particular cards and cases have become so essential to the conduct of the office that appellants, in installing them, must be considered as having intended that they should become so much a part of the indispensable accessories of the operation of the office that the public interest requires that they be not removed. It appears from the record that the former system of card indexing was abandoned. Had that been kept up by appellants at their own expense, and for their own convenience, though less efficient than the plan installed, though possibly involving quite as much labor as the new scheme, it could hardly be claimed that appellants could remove it, or even those cards added by their labors or at their own expense.
This index is not required by any specific law, and it is wholly optional with treasurers whether they keep indexes to these records; but they are so far authorized that the public authorities might contract and pay for their making as.conveniences for the use of the officers and the public, and if so procured, while they may not in the strict sense be public records, they are undoubtedly authorized to be made and kept. They are not less public by reason of being made by an officer in the course of his administration of the office. The public have a direct interest in them, not only during the term of office of the incumbent, but indefinitely. State, ex rel., v. Shutts (1904), 161 Ind. 590; State, ex rel., v. Flynn (1903), 161 Ind. 554; Board, etc., v. Mitchell (1892), 131 Ind. 370, 15 L. R. A. 520; Hoffman v. Board, etc. (1884), 96 Ind. 84; Garrett v. Board, etc. (1884), 92 Ind. 518; Hubler v. Board, etc. (1898), 19 Ind. App. 464.
*1375. It has been held that an index is simply a facility for learning the contents of a record, but not a part of the record itself, unless required by the law to be kept. Bishop v. Schneider (1870), 46 Mo. 472, 2 Am. Rep. 533; Chatham v. Bradford (1873), 50 Ga. 327, 15 Am. Rep. 692; Curtis v. Lyman (1852), 24 Vt. 338, 58 Am. Dec. 174. These cases arose upon a conflict of interest between third parties, because of the failure of an officer to keep an index, owing to which fact some of them were misled in cases where no index was required as a part of the record.
6. We are not called upon to determine whether they are so far public records as to constitute primary evidence, without regard to any other fact than their existence in a pub-lie office, though it is manifest that conditions might arise where they might become'secondary evidence, as in case of the loss or destruction of the assessment rolls, though there is authority for their being regarded as public records. Coleman v. Commonwealth (1874), 25 Gratt. 865, 18 Am. Rep. 711; Herron v. McEnery (1881), 1 McGloin (La.) 108; Bell v. Kendrick (1889), 25 Fla. 778, 6 South. 868; Kyburg v. Perkins (1856), 6 Cal. 674.
4. The following statement in the case of Coleman v. Commonwealth, supra, though obiter, so aptly phrases the matter as to commend itself to our approval and judgment, at least as applied to the facts in this case. “ Whenever a written record of the transactions of a public officer in his office, is a convenient and appropriate mode of discharging the duties of his office, it is not only his right but his duty to keep that memorial, whether expressly required so to do or not; and when kept it becomes a public document — a public record belonging to the office and not to the officer; it is the property of the state and not of the citizen, and is in no sense a private memorandum.”
*1387. *137It is said that a public record is one required by law to be kept, or necessary to be kept, in the discharge of a duty imposed by law, or directed by law to serve as a memo*138rial and evidence of something written, said or done. Miller v. City of Indianapolis (1890), 123 Ind. 196; Commonwealth v. Rodes (1833), 1 Dana (Ky.) *595; Cyclopedic Law Diet.
4. The evidence in this case is all to the point that the indexes are indispensable to the discharge of the duties of the office.
8. It is said in the case of People v. Peck (1893), 138 N. Y. 386, 34 N. E. 347, 20 L. R. A. 381, involving the question of the collection of statistical matter from which compilations are made and reports required to be made: “ He is not to collect the facts merely to enable him to discharge his duty, but in the discharge of a duty.” Here, the treasurer did not prepare the indexes in the discharge of a duty imposed upon him to make them, but to aid him and those succeeding him to discharge the duties of the office; but in the discharge of his duties he did invest the office with facilities for the discharge thereof which are highly essential in the efficient discharge thereof, and in which the public, whose servant he was, are deeply interested. The injury to the public from their removal would be greater than the benefit accruing to appellants, and we think it would be inequitable, when appellants have themselves created the situation, to allow them to disturb it. Because appellants were prevented from removing the cases and cards, it does not follow that their property is taken without just compensation, nor are they deprived of their property without due process of law. They cannot complain of a condition of their own creating.
The city has assumed to retain the property under circumstances rendered reasonable by the course of appellants respecting it, and in which the public interest is deeply affected and concerned, and it would be inequitable to allow them to take it.
The judgment is affirmed.