Don't be seduced by the curves, always readcheck the results
Google Books report from 1910 to 1935 a whole series of books whose titles contain the word alluring:
Salads Alluring and New:... (1926); The Sport Alluring (1917); The Sport Alluring: Trap Shooting (1911); Alluring Arizona (1929); Labrador, Newfoundland, Gulf of St. Lawrence Cruises to the Alluring North - Lands that are Different (1935); The County of Labelle Perhaps the Most Beautiful of the Alluring Laurentians Invites Tourists and Sportsmen Especially the Lovers of Hunting and Fishing to Enjoy Its Scenery, Its Mountains, Its Lakes, Its Rivers and Its Forests (1923); Alluring Rockport: An Unspoiled New England Town on Cape ...; Alluring Albany: Handbook for the Port and Back Country (1912); By Alluring Paths (1932); Margaret Reynolds, Collector: Alluring Arkansas: Scrapbook (1920); Riverside: The City Beautiful : a Brief Description of Some of the Alluring Beauties and Scenic Gems which Confront the Visitor at the Metropolis of Southern California's World Famed Orange Belt (1913).
- The expression more alluring gets 66 hits
- The expression alluring pictures gets 32 results
Apparently Apparently, from the Ngrams posted by the OP, suggest that the term "alluring" hit a peak in the 1920s, while the term remarkable has witnessed a steady decreasedecline in usage. I compared the two terms on the same Google NgramGoogle Ngram, with the same criteria fixed by the OP, i.e. 1800 -2008 with a smoothing of 7, and obtained thisthe following result: alluring (blue line) and remarkable (red line).
If you narrow the search between 1900 and 1960, the following Ngram graph is reproduced
The mountain peak that was so impressive in the Ngram posted by the OP is now barely a moundbump, on the contrary it looks quiteit's virtually flat on this chart.
Google Ngrams is a great tool, but it needs to be used wisely, and judiciously. One user mistakenly believed that Ngrams confirmed the termthat raper was a spelling variant of rapist, when in actual fact Google Books was only reporting the many instances when “Raper”, (note the capital letter) was the last name (surname) of a book'san author: Raper vs. Rapist; Why the shift in suffix?.
Please see the following meta posts for more information on the the advantages and drawbacks of using Google Ngrams.