There is a west gallery containing a fine organ which came to the church from the redundant church of Saint Thomas, Regent Street (also known as Archbishop Tenison's Chapel, Kingly Street). See the Musical Notes section of this website for more details. In 1884 a chancel was added by William White
The interior of the church is a cream white. The High Altar is of stone marble top with a slate base. The High Altar contains the authenticated relics of S. Vincent (martyr) and S. Victorinus (martyr).
When the church was first build it was not associated with the catholic revival; however in White Lion Street a mission had been set up by the parish of All Saints Margaret Street, a church which at that time had played a part in the ‘Oxford Movement’ in the West End of London.
The Mission Church under the patronage of All Saints came to stand for a very much more robust and full blooded Catholicism. Saint Silas church and the mission church became linked together under one administration.
Where Father Preedy had taught the fundamentals of the catholic faith, along with boxing and football, Father Archer added the ‘Papalist’ extras such as devotion to the Sacred Heart of Jesus and to Our Lady, so that Saint Silas and All Saints Mission became as famous, or rather infamous, as the church of Saint Saviour, Hoxton, for what was described as extreme Catholicism.
In Father Archer's incumbency Low Mass was frequently said in Latin. Benediction and Exposition of the Blessed Sacrament brought the church into line with the devotional practices of the rest of Western Catholic Christendom. The Children of Mary would meet week by week to say the Rosary together. Marian processions in May were the order of the day and were well supported by girls wearing white veils.
Immediately after High Mass on Sundays in those days, a Latin Mass was said for lapsed Catholics. Indulgencies were to be earned by reciting certain prayers and even by going through certain doors. There was nothing to distinguish Saint Silas, Pentonville, from those churches which were under the jurisdiction of the Cardinal Archbishop of Westminster. The people responded to it and loved it!