These letters were the origin of circulars.
From 1850 until his death he interfered little in affairs of dogma and church discipline, although he addressed to the powers circulars enclosing the Syllabus (1864) and the acts of the Vatican Council (1870).
He has brought together, in the Bureau of American Ethnology in Washington, many hundreds of manuscripts, written by travellers, traders, missionaries, and scholars; and, better still, in response to circulars, carefully prepared vocabularies, texts and long native stories have been written out by trained collectors.
Other names for the circular lines are " circulars " or " isotropic lines."
Moreover, by section 5 of the Money-lenders Act 1900, where any proceedings are taken against the senders of these circulars to infants, if it is proved that the person to whom the document was sent is an infant, the person charged will be deemed to have been cognisant of the fact unless he proves that he had reasonable grounds for believing the infant to be of full age.