The globular cluster system of the galaxy. I. The metal abundances and reddenings of 79 globular clusters from integrated light measurements.

Photoelectric photometry of the integrand light of globular clusters in selected filter passbands has been used to derive estimates of their interstellar reddenings and metal abundances (i.e., [Fe/H]). The uncertainties in these estimates average ±0.03 in E(B - V) and ±0.10 in [Fe/H], which are not much larger than the uncertainties in the estimates derived from the best methods that rely on observations of individual stars in the clusters. Seventy-nine globular clusters have been observed with our technique, which brings to 84 the total number of globular clusters with precise estimates of metal abundance.