Many data needed for problem solving in Chemical Engineering are dispersed over the literature. Also, various systems of units are used, often forcing the user to do tedious conversions before a ‘quick calculation’ can be done. In this companion the authors have compiled those data frequently used in transport phenomena and related subjects. Since all data are in S.I. units a rapid access to various calculations is facilitated. This compendium consists of four parts. The first part provides general information varying from heuristics for quick estimations to S.I. units and their conversions. The second part consists of frequently used mathematics. In addition to general techniques, it contains vectorial and tensorial calculus relevant to hydrodynamics and elementary rheology. The third part is a compendium of transport phenomena and includes data relevant for environmental sciences. A systematic arrangement facilitates its use. In the final part various material properties are presented. Special attention is given to the most common materials: air and water, but also other materials like hydrocarbons, foods and plastics are included. The comprehensive form of the books facilitates its use for students, scientists and professionals.