Māori devised ways to mark vowel length, sporadically at first. Occasional and inconsistent vowel-length markings occur in 19th-century manuscripts and newspapers written by Māori, including macron-like diacritics and doubling of letters. Māori writer Hare Hongi (Henry Stowell) used macrons in his "Maori-English Tutor and Vade Mecum" of 1911, as does Sir Āpirana Ngata (albeit inconsistently) in his "Maori Grammar and Conversation" (7th printing 1953). Once the Māori language was taught in universities in the 1960s, vowel-length marking was made systematic. At Auckland University, Professor Bruce Biggs (of Ngāti Maniapoto descent) promoted the use of double vowels (e.g. "Maaori"); this style was standard there until Biggs died in 2000.