In order to avail themselves of the authorizations set forth in this chapter, the trustees shall adopt resolutions providing for the issuance of the bonds within the limitations herein mentioned, which resolutions shall prescribe the tenor, terms and conditions of such bonds. Such bonds shall be issued as serial bonds, maturing in equal or unequal amounts, at such times and on such occasions as the trustees shall determine. Provided, always, that the last maturing bonds of any issue shall be expressed to mature not later than forty years from their date, and the first maturing bonds of any issue, issued pursuant to this chapter, shall fall due within five years from their date. They shall bear such rates of interest, payable on such occasion, as the trustees shall prescribe, and the bonds shall be in such denominations, shall be payable in such medium of payment, and at such place as such resolutions shall prescribe. All bonds maturing subsequent to fifteen years from their date shall be subject to redemption not later than fifteen years from their date, and on all subsequent interest payment dates prior to their respective maturities. All bonds may be issued with a provision permitting their redemption on any interest payment date prior to their respective maturities. Bonds made subject to redemption prior to their stated maturities may contain a provision requiring the payment of a premium for the privilege of exercising the right of redemption, in such amount as the trustees shall prescribe in the resolutions authorizing their issuance. All bonds that are subject to redemption shall contain a statement to that effect on the face of each bond. The resolution authorizing their issuance shall contain provisions, specifying the manner of call and the notice of call that must be given.