Thanks for the welcome; I know one of the people who have contributed to this post, because they kindly alerted me to it. I am not sure if the original poster has ever been in contact with me; if not, they are welcome to do so. If they care to Google "William Horatio Brown" and Kaye they will no doubt find me; the email address remains the same. Any original material, like the bible, is of course very exciting. Sadly a print of the scan did not come out very clearly but it is certainly legible down to Henry - I assume Louisa is below. As I said above, any further entries beyond these first 4 children who were baptised by Rev Youl 1 April 1823 (which is perhaps when these entries were written), would be very exciting.
The entries look to me to be in WHB's own handwriting - there are lots of examples as he wrote regular petitions and complaining letters to Govt officials. Though of course I guess to a certain extent if parents taught their children to write, they could write in the same way. (Susannah could sign her own name when she married WHB, though with nothing like the fluency of William.) The entries read WH & S Brown (William Horatio and Susannah) - the entry about H M G? Hospital Parramatta is very interesting - I assume he was employed there, probably as a clerk. He was a schoolmaster at Kissing Point during his convict stage in 1812; on his Certificate of Freedom in 1814 he was described as a "comedian" (actor) - which seems very apt, when you consider his life. His free passage back to NSW in 1816 for himself, wife Susannah and daughter Angela was granted on the basis of his schoolmaster experience. He went to Tasmania as clerk to Rev Youl, and held various Govt positions, most of which which he subsequently lost.