How to interpret the French terms cahier and tome in citation

According to the webpage of the Journal de l’École Polytechnique, each cahier corresponds to a one year volume, and tome corresponds to an issue.

In this case, I think the 'cahier' is the volume and 'Tome' is the issue, based on this example but also based on the definition of tome. This Larousse's definition state that a tome is the division of a work.

If you look at the 1900 issue of the journal, you can find advertised for sale (for 3 fr.):

Table de Matières contenues dans les 64 premiers Cahiers, formant 45 Volumes, suivie d'une Table analytique et d'une Table générale par noms d'auteurs.

Which I would think should be translated as

Table of Contents of the first 64 Cahiers, forming 45 Volumes, followed by a subject index and a general index by authors' names.

So the first 64 issues were grouped into 45 volumes (presumably also known as tomes). These were numbered 1 through 64, and 1 through 45, respectively. The numbering of cahiers starts again with after the 64th cahier, with cahier 1, second series.

Thus, the smaller number would probably be translated as "volume" and the larger number as "issue". However, it's clear that the journal considers the "cahier" the primary number, and the "volume" secondary. In fact, in the second series, they seem to have dispensed with tomes or volumes altogether, and use only the cahier number.