These Verascope Richard stereographs were taken around a century ago, and distributed in the form of 45mm*107mm glass slides for parlour entertainment and education. They have been grouped geographically into the categories shown at the top of the page.
The 300dpi images are around 1900*800 pixels to fit on HD computer screens. Lossless PNG compression is used in preference to JPEG compression, since the latter introduces artifacts that are easily visible when viewed stereoscopically.
The glass stereographs contain do more detail than shown here. The fine detail is easily visible when viewing them in a traditional hand-held viewer or, preferably, in a freestanding Taxiphote. While 600dpi scans do show more detail, it is unlikely that 1200dpi scans would be an improvement.
There is no fundamental reason why higher resolution scans could not be made available.