nyctographn.

1891 ‘L. Carroll’ Diary 24 Oct. (1953) II. xiv. 486 Today [sc. 24 Sept.] I conceived the idea of having a series of squares, cut out in card, and devising an alphabet, of which each letter could be made of lines along the edges of the squares, and dots at the corners... I shall call it ‘The Typhlograph’. (24/10/91. Instead of ‘typhlograph’ I have adopted ‘Nyctograph’ at the suggestion of Warner).

1898 S. D. Collingwood Life & Lett. L. Carroll vii. 295 In 1891 he conceived the device..and he named it the ‘Typhlograph’, but, at the suggestion of one of his brother-students, this was subsequently changed into ‘Nyctograph’.

1930 W. de la Mare Eighteen-eighties 236 He invented..poetical acrostics and the nyctograph.

1959 R. Thomson Psychol. Thinking x. 198 Lewis Carroll derived so much from this source [sc. hypnagogic imagery] that he invented a peculiar instrument, the ‘nyctograph’, to enable him to jot down ideas without fully waking up.

1991 New Scientist 2 Mar. 60/1 Lewis Carroll went as far as designing a device he called a ‘nyctograph’ specifically for the purpose of writing down ideas which came to him in bed so he wouldn't have to get out in the cold.