The Bravais distribution is another name for the bivariate normal distribution, (also sometimes called the bivariate Gaussian or Bivariate Laplace–Gauss distribution).
Teugels & Sundt lists the Bravais distribution as the probability density function of the bivariate normal random vector,
X = X1, X2)T
Haight published a simple formula for the bivariate normal:
and refers the reader to a version published in an article in the 1958 Volume 19 of Skandinavisk Aktuarietidskrift. The unnamed author (I was unable to locate a copy of the journal to find the authors name) probably named this distribution after Bravais , who developed and published his study of normal frequency distributions in two and more variables.
 Haight, F. (1958). Index to the Distributions of Mathematical Statistics. National Bureau of Standards Report.
 Teugels & Sundt. (2004) Encyclopedia of Actuarial Science. Wiley.
 Bravais, August, 1846: “Analyse MathCmatique sur les probabilities des erreurs de situation d’un point,” Memoirs Presentes par Divers Savants, 2nd Series, Vol. 9, Institut de France, Acadamie des Sciences, Paris, France, pp. 255-332