For anyone that might be interested:
BRITISH LOGBOOKS IN UK ARCHIVES17th–19th CENTURIESA survey of the range, selection and suitability of British logbooks and related documents for climatic research Clive Wilkinson Climatic Research Unit, University of East Anglia Norwich, NR4 7TJ United Kingdom E-mail
c.w.wilkinson@uea.ac.uk
https://icoads.noaa.gov/reclaim/pdf/Pre-20thC_British_logbooks_report_version_2009_2.pdf
An excerpt from page 6:
ADM 51 (Captains’ Logbooks)The series of captains‟ logbooks run from 1669 to 1853. They comprise 4,563volumes or pieces, each containing between 4 and 10 individual logbooks. There are approximately 25,000 logbooks in total.
Table 1 gives an approximate number of individual logbooks by decade.Decade Logbooks Decade Logbooks1669-1679 130 1770-1779 10011680-1689 227 1780-1789 13111690-1699 956 1790-1799 33901700-1709 1105 1800-1809 73291710-1719 727 1810-1819 22171720-1729 475 1820-1829 7611730-1739 529 1830-1839 8951740-1749 1146 1840-1849 6611750-1759 837 1850-1853 551760-1769 986 Total 24738Table 1. ADM 51-Decadal Range (figures slightly inflated due to year range or decadal overlap in some volumes)