The Lens of Mirth is a poetic riddle intended to amuse the audience, originating in The Gullies of Boarding. The rules of the form are applied by poets to produce individual poems which can be recited. The poem is a single tercet. Use of juxtaposition is characteristic of the form. A form of parallelism is common throughout the poem, in that certain lines use the same placement of allusions. The third line of the tercet reverses the grammatical structure of the second line. The second line of the tercet must expand the idea of the first line. The first line concerns the past. It has seven syllables. The second line concerns current events. It has ten syllables. The third line concerns the future. It has five syllables.