§ 173-f. Every terminable permit, and every amendment to any existing
license, grant, franchise, permit or consent incorporating therein the
terms of a terminable permit, shall contain an irrevocable option for
the purchase by the city, town or village, either directly or through
its nominee or nominees, of all or any part of the property, plant and
equipment of the street surface railroad at any time, at a price agreed
upon or to be ascertained and determined in a manner agreed upon at the
time of the granting of the permit or amendment and to be set forth
therein. Any such permit or amendment may contain provisions for
amortizing out of earnings or in accordance with an amortization
schedule or schedules to be set forth therein, over a period not
exceeding fifty years, the price to be paid for all or such part of the
property, plant and equipment of the street surface railroad and for any
additions thereto or betterments or improvements thereof, so that upon
the exercise of the option the city, town or village, or its nominee or
nominees, shall be required to pay only the unamortized portion of such
price, and may contain any other terms, agreements, stipulations and
conditions as may be authorized by any statute of the state, or as the
city, town or village may deem proper and in the public interest, and
may provide for the termination thereof for any legal cause.