1. The directors of any railroad company heretofore incorporated under any general or special law, or that may hereafter be organized under the provisions of this chapter, may, by a vote of two-thirds of their whole number, at any time change their roadbed, or roadline, or any part thereof, for the purpose of shortening the line or to overcome natural objections thereto, or to secure economy in its construction; and when the capital stock of such company subscribed, and the amount paid thereon, shall be equal to or exceed the amount per mile, including the proposed extension, which, by section 388.040, is required to be subscribed and paid before filing the original articles of association, then such company may, by a like vote of its directors, at any time extend its line or roadbed from either terminus named in its original charter to such other point as shall be named in such proceedings of such company.

2. And whenever the business of any railroad company which may have heretofore organized or which may hereafter organize to construct a railroad of any gauge may demand a change of the gauge thereof, or whenever for other causes such change of gauge may become necessary or desirable, such company may, by a like vote of its directors, change its gauge, if a narrow, to a broad or standard, and if a broad or standard, to a narrow gauge railroad; provided, that if such railroad desiring such change of gauge be a narrow gauge railroad, such change of gauge shall not be made unless the capital stock of said company shall be at least ten thousand dollars per mile of such road constructed, or shall be increased in the manner provided in this chapter to such sum, nor unless there shall be subscribed in good faith at least one thousand dollars per mile of such road constructed or proposed to be constructed, and five percent thereon paid in cash, nor until such company shall pay into the state treasury the sum of five dollars for every ten thousand dollars of increased capital stock made necessary by such change of gauge. Such proceedings in relation to the extension of their road shall be entered on the record of the company, and a copy of such proceedings, with an affidavit as required by section 388.040 endorsed thereon, shall be filed in the office of the secretary of state, and by him recorded and certified as the original articles of association. But nothing contained in this chapter shall be so construed as to authorize such company to change the general route of their line or roadbed, or to avoid running their road through any point named in the original articles of association, or either terminus named therein, or to change the last established terminus except by extension of their road as aforesaid.