The district judge found that the bark, which had been sailing about northwest, changed her course to starboard after hearing the steamer’s whistle, and that, had she not so changed, the steamer would unquestionably have passed her by a good margin without collision. This finding is supported by the evidence, and fixes the primary responsibility for the collision upon the bark. The change of course by the bark was made before the steamer sighted her, and did not mislead the latter’s officers. The libelants, owners of cargo, and therefore not themselves in any fault, further contended that the steamship was not, at the time of collision, navigating at the moderate speed required hv article 13 of the international rules of 1885. 'The district judge so found, and further held that the steamer failed to show that this statutory fault could not have contributed to the collision. The rule cited requires that “every ship * * * shall in a fog, mist, or falling snow, go at a moderate speed.” That the Saale, whose full speed was about 10 knots, was going at 15 knots, is conceded. The atmospheric condition is in dispute on the testimony. All the witnesses from the bark testify that she had been running in a thick fog for about two hours prior to the time of collision. They were of course unable to testily to the atmospheric conditions surrounding the steamer until the moment before the catastrophe. The log of the Saab; reports: “Until 6 p. m., light hazy mist; later, passing fog showers. Gave fog signals according to rules. Compartments closed. Placed double lookout. At 6:40 p. m., set engine telegraph on ‘Standby.’ Somewhat invisible. * * * We, on the bridge, were under the impression of still being able to see a mile oil.” The officers of the Saale. when called to the stand, corroborated this statement as to the impression prevailing on the bridge, but both lookouts, stationed on the how, testified that for about four or five minutes before they saw the bark the steamer was in a fog so dense; that they could not see more than two or three lengths ahead. No change, however, was made in the speed of the Saale until sin;, sighted the Tordenskjold, about a minute before collision, at a distance which the officers on the bridge estimated at from 1,200 to 1,400 feet, and *480the lookouts and boatswain (the latter standing on the foredeck) estimated at from a length to a length and a half (440 to 660 feet). The helm was at once ordered hard a-port, and the engine reversed as soon as possible. There is in fact no contention that there was any failure on the part of the Saale to do all she could to avoid collision after sighting. The whistles of the Saale were heard on the bark, but the bark’s fog horn, though sounded properly, and at regular intervals, was not heard on the steamer until just as she was sighted. We concur with the district judge in the finding that the fog was of such density as made the thirteenth article applicable, and required the Saale to go at “moderate” speed. However free from mist the atmosphere may have been for the hour preceding-collision, the moment she ran her .nose into the bank or jacket of fog in which the bark lay hid it became at once her duty to moderate her speed. The City of Alexandria, 31 Fed. 431; The Trave, 55 Fed. 119. Although the Saale was not in a dense fog until she entered the bank in which the bark was enveloped, we are satisfied from the evidence that for a brief space before sighting—2, 3, 4, or 5 minutes —both vessels were moving in a dense fog, and during that time the steamer in no way reduced her speed of 15 knots. Her full speed was 16 knots, and the testimony shows that from full speed it takes 4 minutes under reversed engines to bring her to a standstill. There is no evidence in the case to show within what time or distance she can be brought to a standstill from a more moderate speed. That a reduction of but one knot from such speed is not a compliance with the thirteenth article, when the atmosphere in which the steamer is moving makes such article applicable, is no longer open to discussion. Whatever may be the demands of passengers, freighters, and postmásters-general as to maintaining the highest speed attainable, controlling authority has prescribed that speed in a fog shall be moderate; and, however difficult it may'be to define the word “moderate” with mathematical precision, it is abundantly settled by similar authority that a reduction of but .1 knot from a full speed of 16 is not a compliance with the rule. The Pennsylvania, 19 Wall. 135; The Nacoochee, 137 U. S. 330, 11 Sup. Ct. 122; The City of New York, 147 U. S. 72, 13 Sup. Ct. 211.

We are further of the opinion that, had the steamer been going at the moderate speed which the thirteenth article requires, she could have cleared the bark. The district judge reached the same conclusion. Elaborate calculations are presented by the appellant to prove the negative of this proposition on the assumption that the steamer, before sighting, was running at the rate of 10 knots. It is not necessary to review these calculations, since, if 10 knots were a speed so great that the steamer could not avoid a vessel lying in her track within the space at which she sighted her,—which the evidence shows to be from twice to three times her own length,— then it was not moderate, under the authorities above cited. She should have reduced to nine, or even eight, knots, and certainly the evidence does not warrant the finding that at that speed she could not have cleared the bark. The decree of the district court is affirmed, with interest and costs.