translation.en: Whewell's worldwide study of the tides resulted in public tide tables and tidal maps that freely provided the harbormasters' knowledge to all ship captains.
translation.zh: 胡威立研究了全球的潮汐规律 做出了一张全球潮汐规律图， 将原来只有港务长才能掌握的潮汐知识 免费提供给了所有的船长。