At the biennial session of the legislature of 1873 an act was passed (Rev. Code, p. 44) by the first section of which the state treasurer was authorized and directed to accept from the Philadelphia, Wilmington & Baltimore Railroad Company, in that and succeeding years, until the legislature should direct otherwise, the annual sum of $27,000, to be paid in equal quarterly payments on the 1st day of July, October, January, and April, the first payment to be made on the then next 1st day of July, in lieu of all taxes which might thereafter become due from said company in each year, under any and all laws of this State, except the tax imposed by chapter 458, Vol. 12, Laws of Delaware. By the last section it is provided that the said company may also pay to the state treasurer, in semi-annual payments, the gross sum of $13,000, in lieu of that tax also. The object of this act was to fix the definite annual sum of $40,000 as the tax to be paid, in parts and times as aforesaid, by the company to the state, so long as the legislature might choose, instead of the taxes to which it and other railroad companies were liable, under the operation of the act taxing railroad and canal companies, passed on the 8th day of March, 1869, (Rev. Code, p. 41,) *127and the chapter aforesaid. At the time of the passage of this act, the Philadelphia, Wilmington & Baltimore Railroad Company was the owner of a railroad running across the state, and having a length of 23.60 miles. By an act passed at the January session of 1877 said company was allowed to unite with itself one other railroad, viz., that running from its main line at a point now called Delaware Junction, to New Castle; and also that part of the old New Castle & French town Railroad between said New Castle and a place called Rodney Station. The first mentioned road was built and owned by the New Castle & Wilmington Railroad Company; the part last mentioned formed a section or portion of the road of the New Castle & Frenchtown Turnpike & Railroad Company. Both those corporations are now by law merged into, or consolidated with, the Philadelphia, Wilmington & Baltimore Railroad Company, and have no longer any operating existence. Their respective roads form, in fact, a branch of the aforesaid main line of said corporation, and are in length 11.40 miles. On the 1st day of March, 1881, the legislature passed the act entitled “ An act to incorporate the purchasers of the Wilmington & Western Railroad, (Volume 16, Laws, p. 526.) This railroad had been built by a corporation of the state called “ The Wilmington & Western Railroad Company,” to maintain a railroad between Wilmington and Landenburg in Pennsylvania,—which failed,—and whose property had been sold by execution process and bought by the subscribers referred to in the title of the act. The object of the act was to enable the new proprietors of the railroad property, as a corporation, to connect its road with that of a company then establishing a through railroad line between Baltimore and Philadelphia, so as to be a part of the said line, or of a continuous line between those cities. By the fourth section of said act it is provided as follows: “That whenever the Delaware Western Railroad, authorized to be constructed by this act, or any branch or extension thereof, shall unite or become consolidated or connected with the railroad, or any railroad company, existing or organized under the laws of any other state, *128so as to form a part of a continuous line of railway, the said Delaware Western Railroad Company, its assignee or assignees, lessee or lessees, shall pay to the treasurer of this state, for the use of the state, a gross annual sum of money payable in equal semi-annual payments on the 1st day of October and the 1st day of April in each and every year, in lieu of other taxes, which gross annual sum shall bear the same proportion to the sum of forty thousand dollars, the amount now paid annually to this state by the Philadelphia, Wilmington & Baltimore Railroad Company in lieu of taxes, which the length of the Delaware Western Railroad in this state, so forming a part of a continuous line of railway, bears to the length of the Philadelphia, Wilmington & Baltimore Railroad within this state; provided, that nothing in this section shall be deemed, taken, or construed to impair or limit the right of the legislature, at any time hereafter, to determine and fix a different amount of money to be paid by said Delaware Western Railroad Company, or assignee or assignees, lessee or lessees, in lieu of other taxes.” Consolidation between the Delaware Western Railroad Company and the ' Baltimore & Philadelphia Railroad Company took place soon after-wards, whereby the aforesaid fourth section became operative ; and the question between the parties in this case is, how much money is to be annually paid to the state, by force of said section ? The length in this state of the road of the Philadelphia, Wilmington & Baltimore Railroad Company at the time (11th April, 1873) of the passage of the act by which the legislature authorized the state treasurer to accept the sum of $40,000, “ till otherwise ordered by the state, in lieu of the taxes for which it was liable under the act of August 11, 1864, and that of April 8,1869, was as before stated, 23.60 miles. That part of the Delaware Western road forming a section of the continuous line of railway contemplated by the section quoted is 21 3-10 miles. The contention of the defendant is that although at the date of the passage ofi the act of 1873, by which an annual payment of $40,000 is permitted to be made to the state by the Philadelphia, Wilmington & Baltimore Railroad *129Company in lieu of other taxes, the length of the road of that company was 23.60 miles, yet, the building of the Brandywine branch, of 2.16 miles, and the legislation of 1877, which effected the absorption and merger of the New Castle & Wilmington Railroad Company, and of that part of the road of the New Castle and French town Turnpike & Railroad Company between New. Castle and what was then Rodney Station, practically added 13.56 miles to the road of the former; thus augmenting the length of the principal road by that number, aud making it 37.06 miles long. Thus considered, the annual sum to be paid by the defendant, by reason of its 21 3-10 miles of road, would be, roughly, about $25,000; whereas, estimating the length of the Philadelphia, Wilmington & Baltimore Railroad at 23.60 miles, it would be, roughly, $37,000— a difference of $12,000 in annual tax.

The question presented to the court, it is thus seen, though technically one of law, is in realty one of mixed law and fact; and the very nature of it, involving, as it does, inquiry into the mind, or intent, of the legislature which passed the act of 1881, is a very embarrassing one,—all the more so, because there is, perhaps, no example of legislation like this act; at least, none has been produced for our consideration. Nor has any definition been given to us of the length of a railroad, as that term is commonly used, in a technical sense even, by railroad officers. We are left to find, out the meaning of the term, as employed in the legislation, the best way we can. In doing so, we naturally resort to analogy. We have several great highways in ¡this State known as state roads; that between Wilmington and Dover forms part of one of them. There are at various places along the entire length of this great, or principal, thoroughfare, several roads (not cross-roads) issuing from it and extending into the adjacent country, some of which are very important highways. As, from time to time, we have to do, judicially, with some of these branches of the grand trunk road, we may properly say—such being a fact within our judicial knowledge, and, we may add, personal, also—that they are never described in *130legal proceedings, or spoken of by witnesses, or in common speech, as part of such state road; nor can we conceive that any one would, in answer to an inquiry how long that part of the state road passing through the state is, from Wilmington to Dover, reckon up the length of every branch of such road on the line between those places, and add the sum to the 48 miles, more or less, such length is generally understood to be. Take also the case of one of the numerous creeks in this state. They all have affluents, or branches. In contemplating the length of a creek, does any one think of more than the distance from its source to its mouth in some larger water ? The same is the case with a tree. It has branches which are part of its arboreal system, as lateral highways are of state roads systems, and affluents of creek systems. Are the branches or limbs of a tree ever in contemplation, in estimating its length, or, more correctly, height ? Certainly we think not. With the foregoing analogies, it does appear that we have the way cleared for a satisfactory decision as to what was meant by the legislature, in the act of 1881, by the provision for tax of what is now the defendant company in this proceeding. And that conclusion is fortified by the language used in framing the above-quoted fourth section thereof. The company, in the event of consolidation, is to pay “ a gross annual sum which shall bear the same proportion of the sum of forty thousand dollars, the amount now paid by the Philadelphia, Wilmington & Baltimore Railroad Company in lieu of taxes, which the length of the Delaware Western Railroad in this state, so forming a part of a continuous line of railway, bears to the length of the Philadelphia, Wilmington & Baltimore Railroad within this state.” In view of the foregoing analogous interpretation of the term “ length,” when applied to the subjects mentioned, can it be fairly supposed that the legislature of 1873 intended to include branches, or lateral additions, that might be made or become the property of the Philadelphia, Wilmington & Baltimore Railraod Company, (none had been made or acquired at that time,) and treat them as coming within the commutation provision ? We think *131not; but rather that the annual payment was with reference to the then operated road of 23.60 miles in length. If this be reasonable, then it is a fair and just inference that, when the act of 1881 came to be passed, the length of road of the Philadelphia, Wilmington & Baltimore Company was, in the mind of the legislature, its trunk line alone, and not its Brandywine branch, nor the 11.40 miles addition, (beginning on its road at what is called Delaware Junction,) which are now treated, and were before the passage of that act, as part of the Delaware Railroad system; although, correctly speaking, that road extends no further than the former Rodney Station on the Hew Castle & Frenchtown Railroad, where the 11.40-miles branch of the Philadelphia, Wilmington & Baltimore Railroad ends. But it is not material, whether such addition was so treated or not. In our opinion, the gross annual sum of money payable in equal semi-annual payments on the 1st day of October and the 1st day of April in each and every year, due from the said defendant to the said plaintiff, is the sum of $36,101.69; or the proportion to $40,000 which the length of the Baltimore & Philadelphia Railroad of 21 3-10 miles bears to that of the Philadelphia, Wilmington & Baltimore Railroad Company of 23 60-100 miles, as contemplated, in our own opinion, by the legislature in the act of March 1,1881.