This monograph intends to give a general survey of the different
branches of the geometry of linear displacements which so far have
received attention', The material on this new type of differential
geometry has grown so rapidly in re cent years that it is impossible,
not only to be complete, but even to do justice to the work of the
different authors, so that a selection had to be made, We hope, however,
that enough territory is covered to enable the reader to understand the
present state of the theory in the essential points, The author wishes
to thank several mathematicians who have helped hirn with remarks and
suggestions; especially Dr. J. A. SCHOUTEN of Delft and Dr. N. HANSEN
BALL of Princeton. Cambridge, Mass., October 1933. D. J. STRUIK.
Contents. Page Introduction .... . I. Algebra ..... . 5 1. Vectors and
tensors in E n 5 2. Densities . . . . 6 3. Measuring vectors . 7 4.
Point algebra. . . 8 5. The general manifold X" 9 6. Non-holonomic
measuring vectors . 10 7. Pseudotensors ...... . 12 11. Affine
connections .... . 13 1. The principle of displacement 13 2. Affine
displacement Ln 14 3. Torsion. . . . . . 17 4. WEYL connection . 18 5.
Metrical connection 19 6. Curvature. . . 19 7. Integrability 20 8. Some
identities 21 9. Non-holonomic systems 22 10. Transformation groups 23
IH. Connections associated with differential equations 24 1. Paths
........ . 24 2. Projective transformations 25 3. THoMAs parameters . .
.