Appeal from the District Court, Nineteenth-Judicial District, City and County of San Francisco.

By the Act of 1871-2, referred to in the opinion, a belt of land extending from Montgomery street near Washingington street, northerly, was taken and dedicated for a public street, to be known as “Montgomery Avenue." This belt of land is eighty feet wide, and is in the thickly settled part of the city of San Francisco. The Act provided that the value of the land taken for the avenue, and the damages to the improvements thereon, or adjacent thereto, injured thereby, and all other expenses, whatsoever, incidental to the taking and opening of said avenue, should be held and considered to be the cost of opening the avenue, and should be assessed on the lands mentioned and described in the Act, in proportion to the benefits accruing therefrom to the several lots, subdivisions and pieces of land respectively, ■which were by the Act declared to be benefited by opening the avenue. The Act then described particularly by metes and bounds the district which should be deemed benefited by the improvement, and within which the lots and pieces of land should be assessed, but there was a proviso exempting from assessment all lands belonging to the United States or the State of California. A Board of Public Works was created by the Act, consisting of the Mayor, the Tax Collector, and the City and County Surveyor, whose duty it was, among other things, to ascertain the value of the several lots, and the damages to be sustained and the increased value of the several lots caused by the improvement. To pay the expenses, bonds were to be issued in sums of not less than one thousand dollars each, payable in thirty years, bearing interest at six per cent, per annum, to be designated as “ Montgomery Avenue Bonds.” To pay the interest on said bonds, there was to be “levied, assessed and collected annually, at the same time and in the same manner as other taxes are levied, assessed and collected in said city and county, a tax upon the lands” described in the Act. After the year 1880, to pay the principal of the bonds, an annual tax of one per cent, on each §100, of valuation, was to be levied on the same property. The Act declared that these assessments “shall be adjusted and distributed according to the enhanced values of the respective parcels of land, as fixed in the said final report by the said Board.”

This was an application for a writ of prohibition.

Under the act, the Board of Public Works proceeded to estimate the cost of opening the avenue, ’and ascertained that it would be $1,244,736.26, and that the property adjacent would be enhanced in value in the sum of $6,816,-261.84. Of this latter amount, however, it was found that $800,000 would accrue to property belonging to the United States, to the State of California, and to the city and county of San Francisco; and, accordingly, that amount was deducted from the total estimated enhancement of values. The report was confirmed by the County Court, and subsequently, to meet the cost of the enterprise, bonds of the denomination of §1,000 each, bearing interest at the rate of six per cent, per annum, and running thirty years, were prepared to the amount of $1,500,000. At the commencement of this proceeding, in December, 1873, bonds to the amount of $979,000 had been issued. A portion of them had been sold in the market at par, but most of them were sold at a discount, bringing from eighty to eighty-seven and a half cents on the dollar. In October, 1873, the Board of Public Works made a calculation of the sum of money required to pay the interest on the bonds, estimating that, on the first day of January, 1874, bonds would be issued to the amount of §1,000,000, which would require $30,000 to pay the interest then to become due; and that, by July, 1874, the whole amount would be issued, requiring §45,000 more for interest, making in all $75,000. To raise that sum, they fixed upon a rate of assessment of $1.25 on the $100, to be levied upon the $6,016,261.84, estimated and enhanced values over and above the-$800,000 of benefits estimated to accrue to public property. Their action was reported to the Board of Supervisors, and thereupon an ordinance was passed levying the assessment accordingly. The assessed value of the property in the district concerned, irrespective of the estimated increase in values, was $16,000,000.

The petitioners, 3". T. Doyle and W. C. Ralston, were joint tenants of a parcel of land valued at $5,250, which was taken for the avenue, and also of another parcel not taken, and which it was estimated would be enhanced in value to the amount of $12,000. They applied for a writ to prohibit the collection of the assessment, which they claimed to be a tax. An alternative writ was granted. The respondent answered. And after hearing of the cause, the Court dismissed the alternative writ, whereupon the petitioners appealed.