The law did not have provision for a penalty for those who failed to register. That changed in 1874 or 1875, I forget which. I have read that some families christened children that year, sometimes in bulk, to save civil registration fees. Sometimes the register will record the birthdate. A similar situation seems to have occurred in Scotland after civil registration began 1855 and I have seen several examples of births entered in the parish register that year of all the children of a couple, some being born 10 or more years previous. Adrian Verry