For the purpose of providing funds to carry out the provisions of this act, the township board of such township shall at its annual meeting, levy a sufficient tax, in addition to other taxes now authorized by law, upon the real and personal property subject to taxation in such township, and such taxes shall be collected as other taxes are collected, and when collected shall be applied to the payment of any indebtedness incurred by any township coming under the provisions of this act, and to no other purpose: Provided, That the taxes assessed, levied and collected shall not cause the limit of taxes established by law to be exceeded.