To the Honorable the House of Representatives of the Commonwealth of Massachusetts:

The order adopted on the twenty-fourth day of March, 1915, a copy of which is hereto annexed, has been received and the following opinion is submitted.

The question presented is whether Articles XXI and XXII of *611the Amendments to the Constitution require the State decennial census to be taken as of the first day of May, or whether the exact time within the designated year may be fixed by the General Court. The decisive words of Article XXI are these: “A census of the legal voters of each city and town, on the first day of May, shall be taken and returned into the office of the secretary of the Commonwealth, on or before the last day of June, in the year one thousand eight hundred and fifty-seven; and a census of the inhabitants of each city and town, in the year one thousand eight hundred and sixty-five, and of every tenth year thereafter.” Precisely the same words occur in Article XXII of the Amendments.

The natural and ordinary meaning of these words is that the date as of which the enumeration shall be made and when it shall be returned into the office of the secretary of the Commonwealth is defined for the year 1857; but it is not stated for the year 1865 or any subsequent period. No later provision of either article of amendment discloses a different purpose. The apportionment of the representatives to the several counties required by Article XXI must be made by the Legislature “at its first session after the return of each enumeration as aforesaid.” The boards of public officers authorized to divide the counties into districts are required to assemble “ on the first Tuesday of August next after each assignment of representatives to each county” for the performance of their duties. By Article XXII, “The General Court shall, at its first session after each next preceding special enumeration, divide the Commonwealth into forty districts” for the election of senators. These requirements do not point to any particular or unvarying date for taking the census. Articles XXI and XXII, which were adopted in 1857, supplanted respectively Articles XII and XIII of the Amendments. Those articles by unmistakable language made necessary the taking of each successive decennial census in the month of May. The words of Article XII as to the time when the census should be taken, were these: “A census of the ratable polls, in each city, town, and district of the Commonwealth, on the first day of May, shall be taken and returned into the secretary’s office, in such manner as the Legislature shall provide, within the month of May, •in the year of our Lord one thousand eight hundred and thirty-seven, and in every tenth year thereafter, in the month of May.” *612The words of Article XIII are equally unequivocal in designating the month of May and are these: “A census of the inhabitants of each city and. town, on the first day of May, shall be taken, and returned into the secretary’s office, on or before the last day of June, of the year one thousand eight hundred and forty, and of every tenth year thereafter.” The refusal to follow this plain provision of the earlier amendments in adopting the amendment now in force and the use of words naturally conveying a different meaning indicates that the people intended to make a change in this respect. The convention of 1853 included among its constitutional propositions one beginning with these words: “A census of the inhabitants of each city and town in the Commonwealth, on the first day of May in the year one thousand eight hundred and fifty-five, and on the first day of May of each tenth year thereafter, shall be taken and returned into the secretary’s office, on or before the last day of the June following the said first day of May in each of said years.” Although this with the other propositions of that convention was rejected by the people in November, 1853, its provisions doubtless were familiar to the public men who composed the Legislature of 1856 by which Articles XXI and XXII of the Amendments were first adopted.

If it had been the purpose of the framers of Articles XXI and XXII of the Amendments that each census should be taken during the month of May, it would have been easy to express that purpose in simple and direct phrase so clear that it could not be misunderstood. Three models of apt words in suitable form to convey that meaning were at hand in the existing Articles XII and XIII and the proposition of the convention of 1853. The adoption of words of a contrary import cannot be treated as accidental, but must be construed as manifesting a settled design to alter the provisions of the earlier amendments on this point as to each census following that of 1857. This is in conformity with the true theory of a constitution which is to establish only broad principles and to leave details to be wrought out by the Legislature according to the varying demands of policy and expediency.

It follows that under the constitutional provisions now in force the General Court may fix the first day of April as the date as of which the State census must be taken in any tenth year following 1865.

*613The first of May was assumed to be the date of the census in Opinions of the Justices, 142 Mass. 601, 604, 605, and 157 Mass. 595, 596. But that question was not there presented for determination, and was not discussed. Doubtless no date other than May first was thought of then or at any time until after the passage of statutes fixing the first of April in place of the first of May as the date as of which taxes must be assessed.* The references in those opinions to the first of May are not authorities against the conclusion now reached.

Accordingly the first question is answered “Yes” and the second “No.”

Perhaps the third question becomes immaterial in view of the foregoing answers. But plainly it is within the constitutional power of the Legislature to order the census to be taken on the first day of May in the current year and thus change St. 1914, c. 692, requiring it to be taken as of April first.

Arthur P. Rugg.

William Caleb Loring.

Henry K. Braley.

Charles A. De Courcy.

John C. Crosby.

Edward P. Pierce.

James B. Carroll.