Among the editions of Les Prophéties by Nostradamus published in Lyon in 1557, at least two surviving print specimens have been identified. One is the well-known copy held at the National Széchényi Library in Budapest, and the other is a copy rediscovered by Wouter Weijland at the University Library of Utrecht in the Netherlands. Based on its colophon date, the Utrecht copy is thought to have been published earlier than the Budapest specimen; however, its detailed composition and printing characteristics have mainly remained unexplored until now.　This paper examines the bibliographical features and typographic structure of the Utrecht copy and investigates their genealogical relationship through a comparative study with the Budapest copy. To this end, quantitative visual comparison methods—including the Structural Similarity Index (SSIM) and Principal Component Analysis (PCA) based on Histogram of Oriented Gradients (HOG) features—are employed to numerically assess the degree of typographic and printer-related commonality or independence.　

The analysis reveals that, despite surface-level visual similarities, the two copies exhibit only moderate concordance in typefaces and ornamental features, suggesting that they were not direct reproductions from the same printing workshop. Nonetheless, some striking similarities preclude a simple classification of the two as unrelated pirate editions. Instead, a new interpretation emerges: they may represent “technical parallels” produced by sibling workshops or within the same typographic lineage.

This quantitative analysis of the two variant editions of the 1557 Prophéties is likely the first of its kind and provides a cautious but significant opportunity to reassess conventional bibliographical understanding.This quantitative analysis of the two variant editions of the 1557 Prophéties is likely the first of its kind and provides a cautious but significant opportunity to reassess conventional bibliographical understanding. 

1. Bibliographical Information 

2. The Discovery of the 1557 du Rosne Edition

3. Characteristics of the Utrecht Copy

4. Quantitative Analysis of the Two Copies

Conclusion

Bibliography

Report:re_L0005e, 2025/06/19

A Twenty-Year Revision of the 1557 Lyon Edition: Utrecht Copy, as Part of the Seshat Project — Now Including a Quantitative Comparative Evaluation of the Two 1557 du Rosne Editions.