Gergonne (1771-1859), [182], [184]

Greek geometry, [161]

Hachette (1769-1834), [179], [184]

Harmonic conjugates, [29], [30], [39]

Harmonic elements, [86], [49], [91], 163, [185]

Harmonic lines, [33], [34], [35], [66], [67]

Harmonic planes, [34], [35]

Harmonic points, [29], [31], [32], [33], 34, [35], [36], [43], [71], [161]

Harmonic tangents to a conic, 91, [92]

Harvey (1578-1657), [169]