https://www.google.com/books/edition/Manuel_of_Eames_Cursive_Shorthand_by_the/2Bk9AAAAYAAJ?hl=en&gbpv=0

Manuel of Eames Cursive Shorthand by the Card System<br /> A Reporting System with Longhand Movement, in which the Vowels and Consonants are Joined in the Order of Their Occurrence, Including a Remarkable Discovery in Pedagogics which Reduces the Time of Learning at Least One-half

http://www.engramma.it/eOS/index.php?id_articolo=3986

Appears to be a row of slip boxes behind Aby Warburg in this photo of his study in Hamburg from 1917.