Nr. 374
Möbius strip with a sphere as boundary curve
Row: 1

Nr. 296
Boy's surface with three critical points
Row: 1

Nr. 282
Infinitesimal neighbourhood of a line congruence
Row: 2

Nr. 280
Infinitesimal neighbourhood of a line congruence
Row: 2

Nr. 281
Infinitesimal neighbourhood of a line congruence
Row: 2

Nr. 419
10 pairwise orthogonal lines
Row: 3

Nr. 347
Tetrahedron in the projective space
Row: 3

Nr. 898
Stereoscopic pictures of crystal grids from v. Laue and v. Mises
Row: 4

Nr. 899
Zeiss stereoscope
Row: 4