The said payments by insurance companies shall be made quarterly in advance, on the 1st of January, 1st of April, 1st of July, and 1st of October in every year; the first of such payments to be made on the 1st of January one thousand eight hundred and sixty-six, and such first payment and the other payments for the year one thousand eight hundred and sixty-six to be based upon the amounts insured by the several companies in respect of property in the metropolis in the year ending the twenty-fourth of December one thousand eight hundred and sixty-four: provided that any insurance company which at the time of the passing of this Act contributes to the expenses of the said fire engine establishment may, in respect of all payments to be made by it in the years one thousand eight hundred and sixty-six and one thousand eight hundred and sixty-seven, but not afterwards, contribute after the yearly rate of thirty-five pounds in one million pounds of the business in respect of which it contributes to the said fire engine establishment for the present year, according to a return which has been furnished to the chairman of the said Metropolitan Board, instead of in the manner in this Act provided. 14. All contributions due from an insurance company to the Board in pursuance of this Act shall be deemed to be specialty debts due from the company to the Board, and be recovered accordingly. 15. For the purpose of ascertaining the amount to be contributed by every such insurance company as aforesaid, every insurance company insuring property from fire in the metropolis shall, on the thirtieth day of December one thousand eight hundred and sixty-five, with respect to the amounts insured in the year one thousand eight hundred and sixty-four, and on the 1st of June one thousand eight hundred and sixty-six, and on every succeeding 1st of June, or on such other days as the Metropolitan Board of Works may appoint, make a return to the said Board, in such form as they may require, of the gross amount insured by it in respect of property in the metropolis. There shall be annexed to the return so made a declaration made by the secretary or other officer performing the duties of secretary of the company by whom it is made, stating that he has examined the return with the books of the company, and that to the best of his knowledge, information, and belief, it contains a true and faithful account of the gross amount of the sums insured by the company to which he belongs in respect of property in the metropolis. The return made in the June of one year shall not come into effect till the 1st of January of the succeeding year, and shall be the basis of the contributions for that year.