This hanky edging is a pattern called Dainty Tatted Edge on pp 86 from Angeline Crichlow's book 'Let's Tat'. Thank you, Fox.
In the book, Angeline did explain that it was taken off a handkerchief tatted by Margaret Robinson in the 1880s in thread size 80 and 90. Here I used thread size 40.
The above is a sample in my notebook tatted in size 80.