The dot product notation was first introduced by the American physicist and mathematician J. Willard Gibbs in a pamphlet distributed to his students at Yale University in the 1880 s. The product was originally written on the baseline, rather than centered as today, and was referred to as the direct product. Gibbs's pamphlet was eventually incorporated into a book entitled Vector Analysis that was published in 1901 and coauthored with one of his students. Gibbs made major contributions to the fields of thermodynamics and electromagnetic theory and is generally regarded as the greatest American physicist of the nineteenth century.