Bishop Calloner said Mass secretly in alehouses and attics.

The devil, who very well knows that such souls as apply themselves seriously to mental prayer will be none of his, makes all possible efforts to divert Christians from this application by a thousand impostures; and to frighten them with phantoms of imaginary difficulties. But this very opposition of his ought to convince us of the great importance of this exercise and to make us more eager to pursue it, in spite of all his lies and deceits. He pretends the practice of mental prayer is not for all, but only for such as live in convents or colleges; that it requires wit and learning; and that the exercise of it is very difficult. But all this is nothing but a delusion, it is all imposition and lies. Mental prayer, by the way of meditation, is very easy, even to the meanest capacities. It requires nothing but a good will and a sincere desire of conversing with God, by thinking of him and loving him.

– Bishop Richard Challoner, from Considerations upon Christian Truths and Christian Duties Digested into Meditations for Every Day in the Year

Bishop Richard Challoner (1691-1781) was an English Roman Catholic bishop and scriptural scholar perhaps best known for his revision of the Douay-Rheims translation of the Bible, the translation commissioned in direct response to the English Protestant revolt of the previous generation. His own life as a Catholic priest in England of his day testifies that life had not much improved for Catholics—as he was often forced celebrate Mass secretly in alehouses and attics around London. One of his best-known works is an account of the English martyrs who suffered at the hands of their Protestant captors.