Braille worked tirelessly on his ideas, and his system was largely completed by 1824, when he was fifteen years old. From Barbier's night writing, he innovated by simplifying its form and maximizing its efficiency. He made uniform columns for each letter, and he reduced the twelve raised dots to six. He published his system in 1829, and by the second edition in 1837 he had discarded the dashes because they were too difficult to read. Crucially, Braille's smaller cells were capable of being recognized as letters with a single touch of a finger.