Prosodia Rationalis is the short title of the 1779 expanded second edition of Joshua Steele's An Essay Towards Establishing the Melody and Measure of Speech, to be Expressed and Perpetuated by Peculiar Symbols published in 1775. In this work Steele proposes a notation for linguistic prosody; the notation is inspired by that used in music. The treatise is notable as one of the earliest works in the subject and its insight that in speech, unlike in most music, pitches slide rather than exhibit distinct tones held for lengths of time. In 1774 James Burnett, Lord Monboddo published the second of 6 volumes of his On the Origin and Progress of Language containing, among much else, a section dealing with "language considered as sound". Sir John Pringle asked Joshua Steele to respond to some of Monboddo's statements the statement: That there is no accent, such as the Greek and Latin accents, in any modern language.... We have accents in English, syllabic accents too. Now I appeal to them, whether they can perceive any difference of tone betwixt the accented and unaccented syllable of any word?

And if there be none is the music of our language, in this respect, nothing better than the music of a drum, in which we perceive no difference except that of louder or softer. Steele's objection occupies most of the first 2 Parts of Prosodia Rationalis, but as each section of Steele's argument was completed, he sent it off for Lord Monboddo's comments, which were incorporated along with Steele's replies in subsequent sections of the book: "consequently, Prosodia Rationalis is, in effect, an extended dialogue between the two men, to, appended, in the second edition, an additional series of questions from other hands, together with the author's replies." Steele proposed that the "melody and measure" of speech could be analyzed and recorded by notating five distinct types of characteristics, the "five orders of accidents". These are broadly analogous to the suprasegmentals of modern linguistics; the five orders are: Accent: the pitch of the syllable, not—as in music—a fixed pitch, but rather acute, grave, or circumflex.

Quantity: the duration of the syllable, regarded as semibrief, crotchet, or quaver. Pause: silence or rest, measured by the same durations as quantity. Poize: emphasis or cadence, "a term Steele uses ambivalently and confusedly to denote both the absolute duration between stresses, the stresses themselves..." Steele notes three levels: heavy, lightest. "Heavy" is equivalent to the Greek thesis, "light" to the Greek arsis, hence in his quasi-musical notation every bar begins with a heavy element. Force: the loudness of the syllable, marked as loud, soft, or softer.

Eucalyptus signata is a tree native to eastern Australia. It is one of many trees known as the Scribbly Gum; the habitat is dry eucalyptus swampy areas at low altitude. Occurring from Morisset, New South ranges to beyond the Queensland border; the original specimen was collected at the Brisbane River. A small to medium-sized tree, up to 25 metres tall. Related to Eucalyptus haemastoma, however with smaller flower buds and gumnuts. Fruit more hemispherical being 7mm by 7mm in size; the bark is typical of the scribbly gum. White flowers form between September. "Eucalyptus signata". PlantNET - NSW Flora Online. Retrieved 25 May 2010. A Field Guide to Eucalypts - Brooker & Kleinig volume 1, ISBN 0-909605-62-9 page 125