(concurring specially). I concur in the result reached in the majority opinion, but deem it proper to express'my views upon the reasons given by the supervising engineer for refusing to approve of a portion of the sewer. He disapproves of about 2,743 feet of the 10-inch pipe sewer, because it does not stand the light test, in other words, because a light cannot be seen from manhole to manhole. The plans and specifications nowhere call for the light test, and the supervising engineer does not claim that they do, but bases his refusal to approve of that part of the work that will not stand the light test, on the authority of a text-book on Sewers, by Professor Ogden, of Cornell University. The supervising engineer admits that water flows freely through that portion of the sewer disapproved of, and does not claim that the work is not in accordance with the plans and specifications, but bases his refusal to approve wholly on the light test. The supervising engineer cannot arbitrarily or unreasonably withhold his approval of the work. There is no pretense but that the work was done in accordance with the plans and specifications, except that a 24-foot back pressure gate valve to be placed at the river has not been furnished, also that the surface of the streets was not left in as good condition as it was before the commencement of the work. I think the supervising engineer in withholding his approval of the 2,743 feet of sewer on account of its failure to stand the light test is arbitrary and unreasonable, but as the contractor did not furnish the 24-foot back pressure gate valve, and left the surface of the streets in a rough condition, the plaintiff is entitled to relief against paying for that portion of the work. Hence the demurrer was properly overruled.