david is actually incorrect - the population of the Island plateaued at about 50,000 between late 1851 and 1881 with a slight increase in 1891 peaking at around 55,000 in 1901 then decreasing - number of visitors increased very much to 1914 tho many were it seems day visitors (the figures were those paying the 1d landing charge)

My own guess is that you are looking at the same person - the summer boarding house trade would occupy 10-12weeks at most of hard work but little time away from the summer season. Most of those investing in the new boarding houses were from Lancashire not the midlands where most of the 'cotton ballers' as tourists were known as came from