Charles Dickens wrote Little Dorrit between 1855 and 1857. The term circumlocution describes roundabout or indirect speech, or the use of many words where a few would do. The Circumlocution Office is a place of endless confusion. Forms need to be filled in to request permission to fill in more forms.
In this source Mr Clennam has come to the Circumlocution Office to discuss Mr Dorrit's situation in the debtor's prison with Mr Barnacle. Barnacle's speech and personality seems to have been contaminated by the atmosphere of the office.
to ascertain to find out
to ameliorate to better or improve
creditor someone to whom a debt is owed
insolvent unable to pay debts
minute an official note