The availability of ebooks is still hit and miss, particularly for titles even a few years old. I recommend ebookprice.info for ebook searches, but for
Jupiter's Travels : Four Years Around The World On A Triumph all it finds is a Kindle ebook. This appears to be in the TOPAZ format, which typically means that the paper version has been scanned and OCRed by Amazon and converted to an ebook for the Kindle only. Some ebooks start out as TOPAZ (Kindle-only) but eventually also appear as standard ebooks (digitized by the publisher), so there is still hope.