The natural production of radiocarbon by cosmic-ray neutrons has been observed experimentally. Proportional counters, filled with 2 atm of nitrogen, have been employed to detect the exoergic N14(n,p)C14 reaction. Electronic pulse-shape discrimination is utilized to discriminate against meson- and photon-induced events. A C14 production rate of (1.89≠0.08)×10-7/sec/cm3 has been obtained for the air-land interface at the Argonne National Laboratory site. This result represents the average value for a time duration of one month, November-December, 1966. Fluctuations as large as 25% from this average value were observed. The density of slow neutrons can also be determined from this experimental result. An average value of (1.19+/-0.06)×10-8 neutrons/cm3 was found for the air-land interface at the Argonne National Laboratory site (53° N geomagnetic latitude).