Maybe the phrase "this summation" was confusing. So I'll link it one more time, describing as a timeline of the changing estimates of the age of the earth, with dates, names, and links to references. Maybe that will help.
Thank you for your summation. The confusion appears to be on your end, I’m sorry to say.
Just to kick it off, I’ve been wondering just when the age of this Earth became such an all-encompassing issue for science. When did this concern first arise in a major way, and what was the putative age believed to be at that time? And, how has that belief changed over time, to the present? Dating methods in current use must have a very basic, erroneous assumption, in order for science and truth to be so far afield from one another.
The reality seems to be that it's not about finding out when the age of the Earth was first studied and estimated, but with figuring out how to make it look like it originated with Darwin.