Cardboard models of Second Order Surfaces, 1901.
1901
1901
1901
1901
1901
1876
1876
1901
1876
1876
1901
1876
1876
1876
1876
1876
1901
1901
1901
1901
1901
1876
1901
1901
1901
1901
1901
1901
1901
1901
1901
1876