HUMIDITY AND CHRONOMETER RATES.
HUMIDITY AND CHRONOMETER RATES.
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湿度和天文钟速率。
DOI：
10.1126/science.ns-3.57.287
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发表时间：
1884
期刊：
影响因子：
56.9
通讯作者：
D. Todd
中科院分区：
文献类型：
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作者：
D. Todd
作为天文计时器速率变化的一个原因。 1882 年 3 月底左右，他从政府商店借了一只伦敦弗莱彻公司生产的天文钟，它在印度已经有一段时间了，但自抵达以来就没有清理过，据说价格还不错。从6s的增益率开始。 5，保存得相当好的大约两个月，突然下降到2秒的增长速度。 0;这是一系列相当不正常的汇率波动的开始，坦南特少校仔细观察并记录了大约十八个月的时间。首先将这些比率与气象观测站公布的日平均气温图进行比较，结果不太令人满意；因为，虽然乍一看似乎该速率取决于温度，但进一步的检查表明它只能在一定程度上做到这一点，并证实了坦南特少校根据一般印象得出的信念，即该速率并不取决于温度。在温度几乎相同的情况下，速率的巨大差异无疑表明存在速率的周期性变化。坦南特少校认为造成这种情况的原因是湿度。 1883 年，这台天文钟的走时率突然下降，这引起了他的第一次怀疑，当时恰逢第一场大雨产生了巨大的潮湿。事实上，前一年也发生过同样的情况，整个低增长时期是降雨时期，而最低增长时期是降雨结束时的温暖时期，此时土壤通常含有湿气。同样的现象再次出现。然而，如果没有特殊安排，比较假定的因果关系要困难得多。而且，无论如何，空气湿度是否只是一个粗略的指导是值得怀疑的。如果天平轴上的油具有吸湿性，很容易看出它在潮湿的天气中可能会变得更加流动，振荡的弧度会增加，摆轮振动需要更长的时间，并且精密计时器会丢失；但空气的瞬时湿度不会与该速率相对应，而温度或多或少会与该速率相对应。坦南特少校评论了这种特殊情况下毫无疑问的联系，建议在以下方面进行特殊实验：
as a cause of variation in the rate of chronome-ters. He had borrowed from the government-stores about the end of March, 1882,/a chronometer, by Fletcher of London, which had been some time in India, but had not been cleaned since its arrival, and was said to have a good rate. From a gaining-rate of 6s. 5, which it preserved fairly well for about two months, it suddenly fell to a gaining-rate of 2s. 0; this being the commencement of a succession of rather abnormal fluctuations of rate which Major Tennant carefully observed and recorded for about eighteen months. These rates were first compared with a plot of the published daily mean temperatures of the meteorological observatory, with results not quite satisfactory; for, though it would seem at first sight that the rate depends on temperature, further examination showed that it can do so to a moderate extent only, and confirmed the belief, which Major Tennant had from general impressions, that rate does not depend on temperature. The extraordinary differences of rate at times of nearly equal temperature leave no doubt that there is a periodic change of rate; and the cause of this, Major Tennant believes to be humidity. His first suspicion of this was raised by the sudden fall in rate of this chronometer, in 1883, being coincident with the first heavy rains producing great damp; and by the fact, also, that the same thing occurred the year previous, and that the whole period of low gaining-rate was that of the rains, while the lowest was the warm time at the end of the rains, when the soil is generally loaded with nioisture. The same phenomenon recurred. It is, however, much more difficult to compare the supposed cause and effect without special arranlgements; and, in any case, it is doubtful whether air-humidity could be more than a rough guide.If the oil in the arbors of the balance be hygroscopic, it is easy to see that it may become more fluid in damp weather, the arc of oscillation will in-crease, the balance-vibration take longer, and the chronometer lose; but the momentary humidity of the air will not correspond to the rate, as the temnperature does more or less. Major Tennant, remarking the undoubted connection in this particular case, suggests special experimenting in the following di-