Page:Federal Reporter, 1st Series, Volume 9.djvu/893

 878 FEDERAL REPORTER. �The other instructions were strictly correct. The jurj' were not told that the defendant was requiredto adopt every test known to experts to ascertain, the safe condition of the boiler. �If this instruction had been given, within some of the authorities it would not have been erroneous. It haa been frequently declared that the carrier of passengers contracts for their safety as far as human care and foresight can go, (Stokes y. Satonstall, 13 Pet. 181 ; Pa. R. Co. v. Roy, 102 U. S. 451,) and must adopt all the pre- cautions which have been practically tested and are known to be of value, and employ all the skill which is possessed by men whose serv- ices it is practicable for the carrier to secure. Smith v. N. Y. (E H. R. R. Co. 19 N. Y. 127. But the instruction was that the de- fendant was not exculpated if the defect could have been discovered by the application of all tests recognized by experts as necessary., It curely would not express the true extent of the carrier's liability to say that the carrier is exonerated if the defect conld not be discov- ered by the application qi some of the tests which experts recognize as necessary. If there Xvas any test recognized as necesaary which was not applied, the carrier f ailed to comply with its obligation. Of course it was not the suggestion of the instruction that it is the duty of the carrier to adopt all sach speculative and theoretical praeau- tions as might be thought necessary by experts, and the instructions aire not impugned upon this ground. The precautions referred to were those recognized as' necessary by men of practici^l experience in the testing bf steam-boilers. �The more doubtful question presented by the motion for a new trial is whether the jury were justiaed in disregarding the evidence given by the defendant to overthrow the presumption established by the fact of the explosion. It is, doubtless, the general rule that where unimpeached witnesses testify distinctly and positively to facts which are uncontradicted, their testimony sufi&ces to overcome a mere pre- sumption. But when, as here, the testimony proceeds from persons who would be guilty of a criminal fault unless they vindicated them- selves from the presumption arising from the transaction, a question of credibility is presented to the jury. Elwood v. W. U. Tel. Go. 45 N.i. 549. The court might not feel concluded b}' this consideration oh a motion for a new trial, but it would not feel at liberty to set aside the verdict, unless so clearly convinced that the witnesses were entitled to full credit as to be satisfied that the jury were con- trolled by their prejudices rather than by their impartial judg- ��� �