Good question, Rosie!
IGI and/or Parish Registers told me.
So I entered it in my notes, pending denial.
Of course he is only a Joshua - one of many!
But I never got a denial - merely facts (admittedly all about a Joshua; not necessarily him!)
The reason I posted a birth lookup is in the hope we might get "proof" - if there ever is such a thing!
At present all I know is (with the word "a" in front of every JS:-
JS married Mary Kidd 19 Oct 1778 at St Andrews Soham
Mary is a local gal (b Jul 1760 Soham)
JS+ Mary Kidd had these children at Soham between 1781 and 1802:-
Rachel, Jeremiah, John, Mary, Jeremiah, Ann, Mary, John, John, Elizabeth, John, Elizabeth, Charlotte
(that is 4 failed John's!) before suddenly moving to Wortwell, Norfolk and failing with John again and having a Lydia.
Joshua (a Joshua) died at Wortwell, buried in Dissenters ground 15 May 1818 and his Will (NOAH) has an eldest son Jeremiah as executor.
Often Ancestry.con calls Wortwell "Wordwell"!
Here is a bit of history:-
I was working up (back) from my grannie and was stuck around Job Say.
A struggle I will not bore you with (unless you ask!!)
In 1841 we find Job living in Wortwell with his parents Jeremiah and Lydia (both listed aged 50, ie between 45 and 55), and siblings Samuel, Rebecca, Matilda, Joshua and Harriet.
Jeremiah was listed as a farmer.
I found the marriage of Jeremiah Say and Lydia Fennell on the IGI on 22nd January 1816 in Hoxne, Suffolk.
I searched for the birth of Jeremiah Say in the IGI, and found two entries, both for the same family, one for a Jeremiah born to a Joshua Say and Mary in Soham, Cambridge in 1783, though this Jeremiah died in 1787. The second was another Jeremiah to the same parents (this time listed as Joshua Say and Mary Kidd) in the same place in 1788, ie the next son born would have been given the name of the one who had just died, which was of course quite common in those days. The only problem with these entries is that we cannot guarantee there are no more Jeremiah Says out there with different parents, as the IGI is not exhaustive, so this would have to be guesswork.
Wake up
I'm finished!
best wishes
esdel