property beyond its borders is equally uncontested. In these respects tangible personal property is grouped with real property. The legal principle mobilia sequuntur personam operates to permit the taxation of intangible personal property by a State in which its owner is domiciled even though the instruments evidencing its existence and ownership be in another State; and, conversely, it permits the State where these instruments are situated to tax them although their owner be domiciled in another State.

That tangible personal property may be taxed by the State within which it is situated has not been seriously questioned.30

That tangible personal property situated in one State may not be taxed by another State, even though its owner be domiciled therein, is definitely stated in Union Refrigerator Transit Co. v. Kentucky,31 decided in 1905. In this case was presented the question whether a corporation organized under the laws of Kentucky might be assessed upon its rolling stock permanently located in other States and employed there in the prosecution of its business. The court, in its opinion, say: "The argument against the taxability of land within the jurisdiction of another State applies with equal cogency to tangible personal property beyond the jurisdiction. It is not only beyond the sovereignty of the taxing State, but does not and cannot receive protection under its laws. True, a resident owner may receive an income from such property, but the same may be said of real estate within. a foreign jurisdiction. Whatever be the rights of the State with respect to the taxation of such income, it is clearly beyond its power to tax the land from which the income is derived."

Continuing the court point out that the doctrine as to intangible personalty has no application.

& See, for example, Coe v. Errol, 116 U. S. 517; 6 Sup. Ct. Rep. 475; 29 L. ed. 715; Brown v. Houston, 114 U. S. 622, 5 Sup. Ct. Rep. 1091, 29 L. ed. 257, and other cases discussed in § 332 relating to the taxation by the State of articles of interstate commerce.

31 199 U. S. 194; 26 Sup. Ct. Rep. 36; 50 L. ed. 150.

"The arguments in favor of the taxation of intangible property at the domicile of the owner," the court say, "have no application to tangible property. The fact that such property is visible, easily found, and difficult to conceal, and the tax readily collectible, is so cogent an argument for its taxation at its situs, that of late there is a general concensus of opinion that it is taxable in the State where it is permanently located and employed, and where it receives its entire protection, irrespective of the domicile of the owner. We have, ourselves, held in a number of cases that such property, permanently located in a State other than that of its owner, is taxable there." 32

32 After citing earlier cases decided by itself, the Supreme Court continue: "There are doubtless cases in the state reports announcing the principle that the ancient maxim mobilia sequuntur personam still applies to personal property, and that it may be taxed at the domicile of the owner; but upon examination they all, or nearly all, relate to intangible property, such as stocks, bonds, notes, and other choses in action. We are cited to none applying this principle to tangible personal property, and after a careful examination have not been able to find any wherein the question is fairly presented, unless it be that of Wheaton v. Mickel (67 N. J. L. 525, 42 Atl. 843) where a resident of New Jersey was taxed for certain coastwise and seagoing vessels located in Pennsylvania. It did not appear, however, that they were permanently located there. The case turned upon the construction of a state statute and the question of constitutionality was not raised. If there are any other cases holding that the maxim applies to tangible personal property, they are wholly exceptional, and were decided at a time when personal property was comparatively of small amount, and consisted principally of stocks in trade, horses, cattle, vehicles, and vessels engaged in navigation. But in view of the enormous increase of such property since the introduction of railways and the growth of manufactures, the tendency has been in recent years to treat it as having a situs of its own for the purpose of taxation, and correlatively to exempt it at the domicile of its owner." Finally, the court say that the question is, in fact, completely covered in the two recent cases of Louisville & Jeffersonville Ferry Co. v. Kentucky, 188 U. S. 385; 23 Sup. Ct. Rep. 463; 47 L. ed. 513, and Delaware, L. & W. R. Co. v. Pennsylvania, 198 U. S. 341; 25 Sup. Ct. Rep. 669; 49 L. ed. 1077.

The first of these two cases we have already considered. . In the second it was held that including in the appraisement of the capital stock of a domestic corporation, for purposes of taxation, the value of coal mined by it within the State, but situated within other States there awaiting the sale was in excess of the State's taxing power. The supreme court of the State having held that the tax on the value of the capital stock was a tax on the property and assets of the corporation issuing the stock, and it having been repeatedly

§ 534. Taxation of Property Situated in Several Jurisdictions. The instrumentalities through which commerce is carried on between the States and with foreign countries may be taxed by the States as property to the extent that such instrumentalities are within the several territories of the States so taxing them. Thus buildings used for freight and passenger stations and for offices, roadbeds, rails, machine shops, etc., may be taxed by the States in which they are situated, so long as the tax is a general property tax and not one laid upon them specially, nor at a special rate because of their employment in interstate commerce. In determining, however, the value of these properties, the important principle has been laid down that in estimating the value of the property within the State, of a company doing business in several States, the entire property may be treated as a unit and its value in use as such determined, and the value of the part of the prop erty in the particular State estimated as bearing the same proportion to the whole property as the amount of the business done held by the federal Supreme Court itself that a tax on the value of the capital stock of a corporation is a tax on the property in which that capital is invested, and in consequence that no tax can thus be levied which includes property that is otherwise exempt, the court held in the case at bar that the coal actually situated outside of Pennsylvania at the time of the assessment might not be included in the appraisement for purposes of taxation of the capital stock of the plaintiff domestic corporation.. "We regard," said the court, "this tax as, in substance and in fact, though not in form, a tax specifically levied upon the property of the corporation, and part of that property is outside and beyond the jurisdiction of the State which thus assumes to tax it."

The doctrine declared in Union Refrigerator Transit Co. v. Kentucky (199 U. S. 194; 26 Sup. Ct. Rep. 36; 50 L. ed. 150) and the two prior cases upon which that case was rested,- Louisville & Jeffersonville Ferry Co. v. Kentucky (188 U. S. 385; 23 Sup. Ct. Rep. 463; 47 L. ed. 513) and D., L. & W.. R.. R. Co. v. Pennsylvania (198 U. S. 341; 25 Sup. Ct. Rep. 669; 49 L.. ed. 1077), is a recent doctrine. Until these cases were decided the doctrine was generally held and acted upon in many of the States that all personal property, tangible as well as intangible, wherever situated, might be taxed at the domicile of the owner. In Coe v. Errol (116 U. S. 517; 6 Sup. Ct. Rep. 475; 29 L. ed.. 715), decided in 1886, the court say, without qualification, "If the owner of personal property within a State resides in another State which taxes him for that property as part of his general estate attached to his person, this action of the latter State does not in the least affect the right of the State in which the property is situated to tax it also."

in the State bears to the entire business done by the company, or the mileage of tracks of a railway company, or of wires, of a telegraph or telephone company, bears to the entire mileage of tracks or wires of the company taxed.

535. The Unit Rule.

As to railroad, telegraph, and sleeping-car companies engaged in interstate commerce the rule thus is, as stated by the court in Adams Express Co. v. Ohio State Auditor,33" that their property in the several States through which their lines of business extends may be valued as a unit for the purposes of taxation, taking into consideration the uses to which it is put and all the elements making up aggregate value, and that a proportion of the whole fairly and properly ascertained may be taxed by the particular State, without violating any federal restriction.3 The valuation is, thus, not confined to the wires, poles, and instruments of the telegraph company; or the roadbed, ties, rails, and spikes of the railroad company; or the cars of the sleeping-car company, but includes the proportionate part of the value resulting from the combination of the means by which the business was carried on, a value existing to an appreciable extent throughout the entire domain of operation. And it has been decided that a proper mode of ascertaining the assessable value of so much of the whole prop erty as is situated in a particular State is, in the case of railroads, to take that part of the value of the entire road which is measured by the proportion of its length therein to the length of the whole (Pittsburg, C., C. & St. L. R. Co. v. Backus, 154 U. S. 439; 14 Sup. Ct. Rep. 1114; 38 L. ed. 1031); or taking as the basis of

33 165 U. S. 194; 17 Sup. Ct. Rep. 305; 41 L. ed. 683.

34 Citing Western U. Tel. Co. v. Mass., 125 U. S. 530; 8 Sup. Ct. Rep. 961; 31 L. ed. 790; Mass. v. Western U. Tel. Co., 141 U. S. 40; 11 Sup. Ct. Rep. 889; 35 L. ed. 628; Maine v. Grand Trunk R. Co., 142 U. S. 217 12 Sup. Ct. Rep. 121; 35 L. ed. 994; Pittsburg, C. C. & St. L. R. Co. v. Backus, 154 U. S. 421; 14 Sup. Ct. Rep. 1114; 38 L. ed. 1031; Cleveland, C. C. & St. P. R. Co. v. Backus, 154 U. S. 439; 14 Sup. Ct. Rep. 1122; 38 L. ed. 1041; Western U. Tel. Co. v. Taggart, 163 U. S. 1; 16 Sup. Ct. Rep. 1054; 41 L. ed. 49; Pullman Palace Car Co. v. Penn., 141 U. S. 18; 11 Sup. Ct. Rep. 876; 35 L. ed. 613.

assessment such proportion of the capital stock of a sleeping-car company as the number of miles of railroad over which its cars are run in a particular State bears to the whole number of miles. transversed by them in that and other States (Pullman's Palace Car Co. v. Pennsylvania, 141 U. S. 18; 11 Sup. Ct. Rep.. 876; 35 L. ed. 613); or such a proportion of the whole value of the capital stock of a telegraph company as the length of its lines within a State bears to the length of its lines everywhere, deducting a sum equal to the value of the real estate and machinery subject to local taxation within the State (Western U. Tel. Co. v. Taggart, 163 U. S. 1; 16 Sup. Ct. Rep. 1054; 41 L. ed. 49)."

§ 536. Adams Express Co. v. Ohio.

35

This "unit in use" principle of valuation received an extensive application in the case of Adams Express Co. v. Ohio State Auditor,36 decided in 1897, for there the actual tangible property within the State was inconsiderable, whereas the value of the entire concern measured by the amount of business done was very great. Furthermore, there was there lacking that physical unity of plant which is found in railroad and telegraph companies. The court, however, said:

"Doubtless there is a distinction between the property of railroad and telegraph companies and that of express companies. The physical unity existing in the former is lacking in the latter: but there is the same unity in the use of the entire property for the specific purpose, and there are the same elements of value arising from such use.

"The cars of the Pullman company did not constitute a physical unity, and their value as separate cars did not bear a direct relation to the valuation which was sustained in that case. The cars were moved by railway carriers under contract, and the taxation of the corporation in Pennsylvania was sustained on the theory that the whole property of the company might be regarded as a unit plant, with a unit value, a proportionate part of which

35 In the earlier part of this quotation the tense has been changed. 36 165 U. S. 194; 17 Sup. Ct. Rep. 305; 41 L. ed. 683.