Sign Language Manual Alphabet

I learn so many new things while I am researching transferware patterns as an editor of the Transferware Collectors Club Pattern and Source Print Database.  I recently entered a 19th century child's plate with sign language images.  The pattern shows hands illustrating the sign language alphabet consonants in two circles surrounding a single hand showing the vowels. It is an example of the British Manual Alphabet which uses two hands rather than the American Manual Alphabet which uses one hand.  I never realized that although Americans, Englishmen, and Australians share a common oral language, they do not share a common sign language!