The first 18 volumes of the International Scientific Series published in both London and New York were reviewed to assess their contribution to transatlantic communication of popular science. The dominant flow of ideas was westwards on topics such as science versus religion, empiricism in psychology, survival of the fittest, jurisprudence versus mental illness, economics and development of cinematography. There was an eastward flow in philology. The preparation of volumes was rushed and many authors merely expanded previous notes, articles and pamphlets. Commercial and idealistic motives