In Pritchard's "Masonry Dissected", an exposure of masonic ritual written in 1730 by a disillusioned ex-mason, we see for the first time something recognisable as the three degrees of modern Freemasonry. On being admitted to a lodge, a new mason naturally progresses through the degrees of Entered Apprentice, Fellowcraft, and Master Mason. There still remains the rank of Installed Master, which comprises the Master in charge of the lodge and its past masters, and involves its own ritual, words and signs, but entails being elected to take charge of the lodge for a year. These are the regular degrees and ranks of "craft" masonry, common to all constitutions. Other, "higher" degrees are optional and require a mason to join a side-order, except in lodges constituted under the Grand Lodge of Scotland, which are empowered to confer the Mark Master Mason degree on Master Masons, as an extension to the second or Fellowcraft degree. (see main article, Freemasonry)