(after stating the facts) : Section 5 of Article IX of the Constitution ordains that “The Legislature shall authorize the several counties * * * in the State to assess and impose taxes for county * * purposes, and for no other purposes.”
Section 5 of Article VIII of the Constitution as amended in 1899, provides that “The powers, duties and compensation of * * * County Commissioners shall be prescribed by law.”
Section 578 of the Revised Statutes makes it the duty; of the County Commissioners to “maintain * * * any * * * highway in their respective counties” and “to approve all accounts against the counties.” Other sections provide that the County Commissioners shall issue warrants on the County Treasurer to pay claims against the county from county funds in his hands.
Section 438 of the Revised Statutes as amended by Chapter 4171, acts of 1893, provides that “The Governor, by and with the advice and consent of the Senate, shall appoint a Board of Pilot Commissioners for each port in this State, to consist of five members, who shall have their offices for four years, unless sooner removed by the Governor; the said board is to consist of citizens of said *210port, and the said commissioners shall be empowered- to' .-act as Port Wardens and to perform all the duties of the ¡same. They shall take the usual oath of office.”
Section 936 of the Revised Statutes of 1892, as amended by Chapter 4370, acts of 1895, provides that “It shall not be lawful for any person to discharge or cause to be discharged, deposit or cause to be deposited, in the tide or salt waters of any bay, port, harbor or river of this Staté any ballast or material of any kind other than clear .stone or rock free from gravel or pebbles, which said clear ,-stone or rock shall be deposited or discharged only in the •construction of enclosures in connection with wharves, piers, jetties, or in the construction -of permanent bulkhéads connecting the solid and permanent portions of wharves.”
Section 950 of the Revised Statutes provides that “The Board of Pilot Commissioners of each port shall take such steps as may be necessary to detect any violation in their port -or waters within their jurisdiction of the laws for the* protection of ports, harbors, bays and rivers; and they shall cause complaint to be made for the arrest of every offender against such laws. And the County Commissioners of the county in which such Pilot Commissioners are appointed shall audit and pay the expenses of the Board of Pilot Commissioners, which shall be incurred under this Section, as other charges against the county are audited and paid.”
It is urged that the expenses incurred by the Board ‘of Pilot Commissioners under Section 950 of the Revised Statutes in detecting violations of the laws for the protection of ports, harbors, bays and rivers are not for a county purpose and are therefore not a valid charge *211upon tlie county; and that the requirements of said section that the County Commissioners shall audit and pay such expenses as other charges against the county are audited- and paid, is not valid because the expenses are those incurred by the Board of Pilot Commissioners in the exercise of powers belonging solely to the County Commissioners, and because no provision is made by the act for the estimate of such expenses to be submitted to the County Commissioners by the Board of Pilot .Commissioners.
Under Section 5 of Article IX of the Constitution, the Legislature cannot authorize the counties to assess and impose taxes except for county purposes; and legislative direction to pay oui for other than county purposes money derived from taxes assessed and imposed by a county would be in conflict with the manifest purpose and intention of the mentioned constitutional provision. It is the duty of the courts to construe legislative acts with reference to the constitution, and if the constitution is. clearly violated by a provision of a statute such provision should be declared inoperative; but if the provision is not clearly in conflict with the constitution, or if there is a well founded or reasonable doubt as to the constitutionality of the provision the legislative will as expressed therein should be sustained. Whether'an expenditure demanded as to be made from the funds derived by a county from taxes assessed and imposed by it by virtue of legislation under the constitution, is or is not for a county purpose, is to be determined by the courts from the facts and circumstances of each particular case; but when an expenditure is authorized by the Legislature as being a county purpose, the courts will not interfere except in cases free from all reasonable doubt. When a county pur*212pose lias been designated by a statute which directs that expenses incurred by certain officers for the protection of ports, harbors, bays and rivers within the county, shall be audited and paid by the County Commissioners as other charges against the county are audited and paid, such designation of a county purpose will, in deference to the legislative department, be recognized and enforced by the courts unless it clearly appears that it is not a county purpose within the meaning of the Constitution. If the payment demanded of a county is for a county purpose, the particular officers engaged and methods used under a statute in incurring the expenditure do not affect its character as a 'county purpose. A river, harbor or bay of a port is a public' highway, useful to the people of the county in which it is situated for the purposes of navigation and commerce. The depth of the water therein is one of the chief elements of its value, and its protection from injury of being filled in, is within the purposes for which county governments are established, even though the harbor or 'bay be also and largely used for passage to and from, and commerce with, points beyond the county. It is competent for the State acting through Hie counties to-protect the ports, harbors, bays and rivers therein if the control of the general government within its sphere is not thereby interfered with. See Cotton v. County Commissioners of Leon County, 6 Fla. 610; Stockton v. Powell, 29 Fla. 1, 10 South. Rep. 688; County Commissioners of Duval County v. City of Jacksonville, 36 Fla. 196, 18 South. Rep. 339; Skinner v. Henderson, 26 Fla. 121, 7 South. Rep. 464; President and Commissioners, etc., v. State ex rel. Board, etc., 45 Ala. 399.
The alternative. writ alleges that the Board of Pilot Commissioners for the port of Pensacola, Florida, has *213from time to time been informed that the harbor of Pensacola is being shoaled and destroyed by the deposition therein by steamships, vessels and individuals, of ashes and ballast and other materials; that said board under Section 950 of the Revised Statutes of Florida employed one harbor policeman to detect any and all violations in the port of Pensacola and the waters thereof of Section 936 of the Revised Statutes. That section makes it unlawful for any person to discharge or cause to be discharged, deposit or cause to be deposited, in the tide or salt waters of any bay, port, harbor or river in the State, any ballast or material of any kind other than clear stone or rock free from gravel or pebbles used under authority of law for improving the harbor.
It is clearly within the power of the State to make provision for the protection of its ports and harbors by preventing the filling in of waters used for navigation and commerce, and it may do this through officers of the county or otherwise. When such port or harbor is within a county it is competent for the Legislature to impose upon the county the burden of protecting such harbor or port, since it affords a means of carriage and commerce, useful to the people of the county, and is within the purposes for which county governments are established. The fact that the protection is to be had under the direction and control of officers other than the County Commissioners does not affect its character as a county purpose. Under the constitution the powers and duties of the County Commissioners are prescribed by statute. The statute does not give them exclusive police or other supervision over the ports or harbors of the State and the Legislature may provide for the exercise of such powers within a county by officials other than the County Commissioners, The" *214Board of Pilot Commissioners are given no power to assess or impose taxes or to pay out county funds, but only to supervise the protection of the harbors, the expenses of which are to be paid by the County Commissioners from county funds.
The Constitution does not require that the Legislature shall impose a limitation upon expenditures incurred for county purposes, and in the absence of such a limitation the Legislature has plenary power within proper county purposes. See Board of Supervisors of Sangamon County v. City of Springfield, 63 Ill. 66.
The respondents urge that the demand is not a proper charge against the county, (1) because there was no necessity for the employment of the harbor policeman, for the reason that the United States government had charge of the harbor or port of Pensacola, and through its officers furnish patrol and protection of said harbor from violations of the laws of the United States for the protection of harbors; (2) because the greater part of the harbor of Pensacola is within the city of Pensacola and under its police protection; (3) because the harbor of Pensacola is within E'scambia and Santa Rosa counties and under their police protection; and further that the County Commissioners have exercised their best judgment and discretion in refusing payment, the port or harbor being in Escambia and Santa Rosa counties and the expense having been incurred by the Board of Pilot Commissioners composed of citizens of E'scambia and Santa Rosa counties without including Santa Rosa county in the liability, and no crime is alleged to have been detected or prosecution begun as the result of the service rendered.
The statute requires the Board of Pilot Commissioners to take such steps as may be necessary to detect any vio*215lation of the laws for the protection of ports, harbors, bays and rivers, and the County Commissioners are required to audit and pay the expenses so incurred as other charges against the county are audited and paid. Under this statute the necessity for incurring expenses in detecting any violations of the law for the protection of ports, harbors, bays .and rivers is to be determined by the Board of Pilot Commissioners, and no duty with reference to it is imposed upon the County Commissioners except that of audiling and paying for such expenses. The statute gives no warrant for the exercise of judgment and discretion in the matter by the County Commissioners. The judgment of the County Commissioners as to the necessity for local protection of a harbor or port, or that such protection will conflict with the authority of the Uuited States, acting within its proper sphere, is not material when the statute makes it their duty to pay the expenses incurred under a statute for a county purpose. If it be that a portion of the port or harbor is within another county, and that the Board of Pilot Commissioners is composed of citizens of both counties, such facts furnish no ground for tlye refusal by the County Commissioners to obey the plain mandate of a valid statute. The statute provides that steps shall be taken to detect violations of the law and that the expenses hereof shall be paid 'by the county. A criminal prosecution or the actual detection of a crime is not a prerequisite to the expenditures provided for. Tf it be true that the greater part of the port or harbor is within the corporate limits of the city of Pensacola and under the protection of the police department of the city, the county is not thereby relieved of its powers and duties with reference to the protection of the port or bay or harbor within its territory. Even if the harbor of Pensacola lies *216within the corporate limits of the counties of Escambia and Santa Rosa, and is under the police protection of such counties, the State Is not thereby precluded from providing for the protection of the portion of the port, bay or harbor within Escambia county at the expense of such county.
When an expenditure by a eounty is authorized by a valid law and the correctness of the amount due by the county is ascertained and approved as the law directs, there being no question as to bona ñdes, it is the duty of the County Commissioners to audit, approve and pay the same, and such payment may be enforced by mandamus.
The demurrer to the alternative writ was properly overruled, and there was no error in sustaining the demurrer to the answer.
The award of the peremptory writ of mandamus is affirmed.
Shackleford, C. J., and Cockrell, J., concur; Taylor, Hocker and Parkhill, JJ., concur in the opinion.