Geometrical crystallography before X-rays describes how geometrical crystallography developed as a science up to the discovery of X-rays by Wilhelm Conrad Röntgen in 1895. In the period before X-rays,
Cannonballs piled on a triangular (front) and rectangular (back) base, both face-centered cubic lattices.
Drawing by Kepler (1611) of square (A) and hexagonal (B) packings
René Just Haüy
Christian Samuel Weiss
Johann F. C. Hessel
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Johann Friedrich Christian Hessel was a German physician and professor of mineralogy at the University of Marburg.
Nineteenth century drawing of Johann Friedrich Christian Hessel
