MO. RIT. PKT. CO. V. H. * ST. J. E. CO. 291 �case presenting that question it might be held that the ob- Btruction to navigation is so slight as to be tolerated, in view of the greater aid to commerce rendered by the structure. This point is not now before us, and no opinion is expressed upon it. It is Buificient to say that if the structure is not according to the limitations of the act of congress it is so far unauthorized, and the defendant is, therefore, liable for any injury to the plaintiff's vessel which was caused, or contrib- uted to, by the unlawful structure; and this is ail that was eaid by the court in charging the jury. �4. It is contended that, although the measurement sanc- tioned by the court should be adopted as the true construction of the act of congress, it does not foUow that the plaintiff can recover, and that the charge is erroneous and mislead- ing in so instructing the jury. The answer to this is that the court did not instruct the jury that the plaintifif must neces- sarily recover if the distance between the piers was less than that required by law, The instruction was, as already shown, that in order to recover the plaintiff must show that the width between the piers was less than the act of congress requires, and also that the unlawful structure "caused or con- tributed to the injury by plaintiff complained of." �Counsel for defendant insist that it was not claimed, on the trial, that the injury resulted from the unlawful construc- tion of the bridge. They say that the gravamen of the charge is that the sinking of the pontoons caused a cross cur- rent to set in towards the bridge, the effect of which was to throw the plaintiff's boat over on the pier. It is quite evi- dent, from the record, that the plaintiff charged the defend- ant with responsibility for two unlawful obstructions in the river, the combined effect of which was to produce the injury to the steamboat Joe Kinney, notwithstanding due diligence on the part of the officers and crew in charge of her. These were, first, the sunken pontoons; and, secondly, the bridge pier. It is also apparent that there was evidence tending to support the plaintiff's theory in this regard ; and, based upon that evidence, the court instructed the jury, with reference to the bridge, in the language above quoted ; and, regarding the ����
