A painter working in Europe in the year 1300 had no reliable method for showing depth. Dis figures we often dr the sa size a nearby on, or sim placed hig on t panel, a buildings leaned in directions that no real building could. Early in the fifteenth century the architect Filippo Brunelleschi worked out the geometry that fixed this, and within a generation every serious workshop in Florence was teaching it. Depth had stopped being a matter of instinct and had become a matter of construction.

Type only the missing letters. Each box is one letter, and the number of boxes matches the letters that are missing.