The construction of an electronic data set of the tidal measurements made at St. Helena in 1761 by Nevil Maskelyne is described. These data were first analysed by Cartwright (1971, 1972) in papers which have importance within studies of changing tides. However, Cartwright's data files were never archived for the benefit of other researchers, demonstrating that “old data” at risk can sometimes take the form of electronic rather than paper records. In the present paper, the newly digitised Maskelyne data have been reanalysed by several techniques in order to obtain an updated impression of whether the tide has changed at that location in over two and a half centuries. This new data set may be found via https://doi.org/10.5285/e66db85a-eaae-6665-e053-6c86abc0bfb9 (Woodworth and Vassie, 2022). Our main conclusion, consistent with that of Cartwright, is that the major tidal constituent (M2) has changed little. However, the results of the various techniques demonstrate how difficult it is to obtain reliable conclusions for the smaller constituents.

中文翻译：

---

1761 年在圣赫勒拿岛重新分析 Maskelyne 的潮汐数据

描述了 Nevil Maskelyne 于 1761 年在圣赫勒拿进行的潮汐测量电子数据集的构建。这些数据首先由 Cartwright (1971, 1972) 在对潮汐变化研究具有重要意义的论文中进行分析。然而，卡特赖特的数据文件从未为其他研究人员的利益而存档，这表明处于风险中的“旧数据”有时可以采用电子记录而不是纸质记录的形式。在本论文中，新数字化的 Maskelyne 数据已通过多种技术进行了重新分析，以便获得关于两个半世纪以来该位置的潮汐是否发生变化的最新印象。这个新数据集可以通过 https://doi.org/10.5285/e66db85a-eaae-6665-e053-6c86abc0bfb9（Woodworth 和 Vassie，2022）找到。我们的主要结论，与卡特赖特的一致，主要潮汐成分（M2）变化不大。然而，各种技术的结果表明，要为较小的成分获得可靠的结论是多么困难。