fore its course of action in respect of oil-bearing lands— whether it has held them to be mineral or otherwise requires to be noticed. The various mining circulars, instructions and decisions, as published from time to time, show that the matter probably was not considered prior to the first mining circular, July 15, 1873, but that since then the Department has regarded petroleum as a mineral and has treated lands chiefly valuable therefor as mineral lands. With a single exception, the rulings have been uniform, and lands of great value have passed into private ownership under them. The single exception is the case of Union Oil Co., 23 L. D. 222, 226, decided August 27, 1896, which was revoked on a motion for review November 6, 1897, 25 L. D. 351. It appears from the later. decision that action upon other pending cases turning upon the same question had been suspended in the meantime, so, practically speaking, there has been no break in the Department's rulings. The case of Union Oil Company presented a controversy between that company and the Southern Pacific Railroad Company over a tract of land in California, the former claiming under a placer mining claim and insisting that the land was chiefly valuable for petroleum and therefore mineral, and the latter seeking a patent under its land grant and insisting that the land, even if chiefly valuable for petroleum, was not mineral. In the original decision the Secretary of the Interior held that the word "mineral" embraced only "the more precious metals," such as "gold, silver, cinnabar, etc.," but on the rehearing this view was rejected and the prior rulings holding petroleum to be a mineral

1 Circular July 15, 1873, Copp's Mineral Lands, 61; Letter of Commissioner Burdett, January 30, 1875, Sickles' Mining Laws, 491; Maxwell v. Brierly, 10 Copp's L. O. 50; Instructions January 30, 1883, 1 L. D. 572; Roberts v. Jepson, 4 L. D. 60; Piru Oil Co., 16 L. D. 117; Union Oil Co., 25 L. D. 351; McQuiddy v. California, 29 L. D. 181; Tulare Oil Co. v. Southern Pacific Railroad Co., 29 L. D. 269.

were reaffirmed and applied, the railroad company's application for a patent being denied.

Notwithstanding these persuasive considerations for now regarding petroleum lands as mineral lands within the meaning of the excepting clause in the granting act, we are asked to give effect to the strictly scientific view that petroleum is a resultant of the decomposition of organic matter under certain conditions of temperature and pressure and therefore is not a mineral. As we understand it, scientists are not in full accord upon this point, some ascribing to petroleum an inorganic origin. Encyclopædia Britannica, 11th ed., Vol. 21, p. 318. But, passing this seeming divergence in opinion and assuming that when subjected to a strictly scientific test petroleum is not a mineral, we think that is not the test contemplated by the statute. It was dealing with a practical subject in a practical way, and we think it used the words "mineral lands," and intended that they should be applied, in their ordinary and popular sense. In that sense, as before indicated, they embrace lands chiefly valuable for petroleum.

Our answer to the fifth question must therefore be in the affirmative.

The other questions are so closely related one to another and turn so largely upon principles of general application to controversies arising out of the public-land laws, including railroad land grants, that it seems the better course to consider them in a general way in connection with those principles, and then to come to the specific answers to be given to them separately.

We first notice a contention advanced on the part of the mineral claimants, to the effect that the grant to the railroad company was merely a gift from the United States, and should be construed and applied accordingly. The granting act not only does not support the contention but refutes it. The act did not follow the building of

the road but preceded it. Instead of giving a gratuitous reward for something already done, the act made a proposal to the company to the effect that if the latter would locate, construct and put into operation a designated line of railroad, patents would be issued to the company confirming in it the right and title to the public lands falling within the descriptive terms of the grant. The purpose was to bring about the construction of the road, with the resulting advantages to the Government and the public, and to that end provision was made for compensating the company, if it should do the work, by patenting to it the lands indicated. The company was at liberty to accept or reject the proposal. It accepted in the mode contemplated by the act, and thereby the parties were brought into such contractual relations that the terms of the proposal became obligatory on both. Menotti v. Dillon, 167 U. S. 703, 721. And when, by constructing the road and putting it in operation, the company performed its part of the contract, it became entitled to performance by the Government. In other words, it earned the right to the lands described. Of course, any ambiguity or uncertainty in the terms employed should be resolved in favor of the Government, but the grant should not be treated as a mere gift.

Two distinct land grants were made to the Southern Pacific Railroad Company, one on behalf of the construction of a main line, and the other (act March 3, 1871, 16 Stat. 573, 579, c. 122, § 23) on behalf of a branch line. We are not here concerned with the latter. The former was made by the act of July 27, 1866, 14 Stat. 292, c. 278. That act first made provision for the construction of a line of railroad, by the Atlantic & Pacific Railroad Company, from Springfield, Missouri, westward through northern Arizona to the Pacific Ocean, and by its third and fourth sections made the following grant of public lands to that company:

"SEC. 3. That there be, and hereby is, granted to the Atlantic and Pacific Railroad Company, its successors and assigns, for the purpose of aiding in the construction of said railroad and telegraph line to the Pacific coast, and to secure the safe and speedy transportation of the mails, troops, munitions of war, and public stores, over the route of said line of railway and its branches, every alternate section of public land, not mineral, designated by odd numbers, to the amount of twenty alternate sections per mile, on each side of said railroad line, as said company may adopt, through the Territories of the United States, and ten alternate sections of land per mile on each side of said railroad whenever it passes through any State, and whenever, on the line thereof, the United States have full title, not reserved, sold, granted, or otherwise appropriated, and free from preemption or other claims or rights, at the time the line of said road is designated by a plat thereof, filed in the office of the commissioner of the general land office, and whenever, prior to said time, any of said sections or parts of sections shall have been granted, sold, reserved, occupied by homestead settlers, or preëmpted, or otherwise disposed of, other lands shall be selected by said company in lieu thereof, under the direction of the Secretary of the Interior, in alternate sections, and designated by odd numbers, not more than ten miles beyond the limits of said alternate sections, and not including the reserved numbers: Provided, further, That all mineral lands be, and the same are hereby, excluded from the operations of this act, and in lieu thereof a like quantity of unoccupied and unappropriated agricultural lands in odd-numbered sections nearest to the line of said road, and within twenty miles thereof, may be selected as above provided: And provided further, That the word 'mineral,' when it occurs in this act, shall not be held to include iron or coal:

"SEC. 4. That whenever said Atlantic and Pacific Rail

road Company shall have twenty-five consecutive miles of any portion of said railroad and telegraph line ready for the service contemplated, the President of the United States shall appoint three commissioners to examine the same, who shall be paid a reasonable compensation for their services by the company, to be determined by the Secretary of the Interior; and if it shall appear that twenty-five consecutive miles of said road and telegraph line have been completed in a good, substantial and workmanlike manner, as in all other respects required by this act, the commissioners shall so report under oath, to the President of the United States, and patents of lands, as aforesaid, shall be issued to said company, confirming to said company the right and title to said lands situated opposite to and coterminous with said completed section of said road. And from time to time, whenever twentyfive additional consecutive miles shall have been constructed, completed, and in readiness as aforesaid, and verified by said commissioners to the President of the United States, then patents shall be issued to said company conveying the additional sections of land as aforesaid, and so on as fast as every twenty-five miles of said road is completed as aforesaid."

By its eighteenth section the act made provision for the construction by the Southern Pacific Railroad Company of a connecting line of railroad from the eastern boundary of California to San Francisco, and in that connection made the grant now under consideration. That section reads:

"That the Southern Pacific Railroad, a company incorporated under the laws of the State of California, is hereby authorized to connect with the said Atlantic and Pacific Railroad, formed under this act, at such point, near the boundary line of the State of California, as they shall deem most suitable for a railroad line to San Francisco, and shall have a uniform gauge and rate of freight or fare