According to the title page of his book, Wetzel was "Lehrer an dem Königl. Lehrerinnen-Seminar und der Königl. Augustaschule in Berlin", out of which experience his desire to create a planetarium capable of various demonstrations, that would be useful for students of varying abilities arose, the introduction notes. Hence, the planetarium can be arranged to show the tellurian within the rings, or the tellurian can be removed, and the second terrestrial globe can be put into the rings, and the rings and ecliptic band rotated around it.
The accompanying book has extensive manuscript amendments pasted over the text in a 19th century German hand, and there are manuscript amendments to the folding plate (e.g. where the plate shows a slightly different tellurian design, it has been corrected to show the design used on the present planetarium, or certain figures have been crossed through, and manuscript corrections made to the text passages relating to the figure). These amendments could suggest that this copy of the book was Wetzlar's own proof copy, with his manuscript corrections for the printer.