A Lewis is an operative tool, Masonic symbol, or young man adopted by a Lodge.

A lewis is an instrument in operative masonry. It is a cramp iron which is inserted into a cavity prepared for that purpose in any large stone, so as to give attachment to a pulley and hook whereby the stone may be conveniently raised to any height and deposited in its proper position. The contrivance was known to the Romans, and several taken from old ruins are now in the Vatican. In addition, in the ruins of Whitby Abbey in England, which was founded by Oswy, King of Northumberland, in 685, large stones were discovered with the necessary excavation for the insertion of a lewis. The word is likely derived from the old French levis, any tool for lifting. The modern French call the instrument a louve.

In the English system of Masonry, the lewis is found on the tracing board of the Entered Apprentice, where it is used as a symbol of strength, because, by its assistance, the operative mason is enabled to lift the heaviest stones with a comparatively trifling exertion of physical power. It has not been adopted as a symbol by American Freemasons, except in Pennsylvania, where it receives the English interpretation.

The son of a Mason is, in England, called a Lewis, because it is his duty to support the sinking powers and aid the failing strength of his father. In the rituals of the middle of the last century he was called a louffton. From this the French derived their word louveteau, and call the daughter of a Mason a louvetine. Louveteau is probably derived directly from louve, the French name of the implement. In Browne’s Master Key, which is supposed to represent the Prestonian lecture, we have, in part, the following dialogue:

Q. What do we call the son of a Freemason?
A. A Lewis
Q. What does that denote?
A. Strength
Q. How is a Lewis depicted in a Freemason’s Lodge?
A. As a cramp of metal, by which, when fixed into a stone, great and ponderous weights are raised to a certain height and fixed upon their proper bases, without which Operative Masons could not so conveniently do.
Q. What is the duty of a Lewis, the son of a Mason, to his aged parents?
A. To bear the heavy burden in the heat of the day and help them in time of need, which, by reason of their great age, they ought to be exempted from, so as to render the close of their days happy and comfortable.
Q. His privilege for so doing?
A. To be made a Mason before any other person, however dignified by birth, rank, or riches, unless he, through complaisance, waives this privilege.

This article, edited for length, is reprinted from the New Orleans S. R. Trestleboard, Nov/Dec 1998. 
Editor’s Note: In 1871, the Supreme Council published "Reception of a Louveteau" by Albert Pike. This 70-page treatise details the rules and ceremonies for a young man being formally adopted by a Masonic Lodge. The public ceremony takes place in the spring. The boy’s mother or godmother is present, dressed in white, as is his father or other near male relative, dressed in black. If any of these are absent or considered unfit, they are replaced by the sisters or wives of Masons or by past officers of the Lodge. There is a special arrangement of the Lodge room, specific ritual paraphernalia, and an elaborate, inspiring ceremony.

The ceremony specifically mentions the age of 14, but it is clear that a Lewis may be younger, but under 21. Ill. Bro. John J. Robinson, 33°, in A Pilgrim’s Path, recommended the revival of this Masonic custom because it can provide beneficial adult guidance to young men during their formative years. Ill. Robinson outlines a ceremony, no longer than 45 minutes, where the young man, ideally age 12, is introduced to the Lodge by his father, a Mason. The Worshipful Master then briefly explains the Lodge and Freemasonry to the young man, accenting that any man in the room "is with your father in Masonic brotherhood. Just as any one of them would help your father, so any of them will help you, if ever you need it." The Lodge then closes with a benediction, refreshments, and the presentation of a gift, such as a baseball cap with the Square and Compasses on it, to the young man.

Ill. Robinson concludes: "That boy will go home and tell his mother, brothers, and sisters what he experienced that night. And what will he talk about to all his friends at school the next day? In terms of membership, he won’t even be eligible to apply for membership for nine more years, but there should be more immediate benefits. He will no longer be puzzled by or feel left out of a part of his father’s life. As to the fatherly complaint about the subject of Masonry expressed in ‘I don’t know how to bring it up,’ that problem is gone. Chances are rather good that his son will bring it up. And when the boy hears that Dad is going to a lodge meeting tonight, he knows very well where his father is going. He’ll feel special" (pp. 140–43).