Absolute frequency measurements, with up to $1\times {10}^{-11}$ level accuracies, are presented for 60 lines of the P and R branches for the ${\nu }_1+{\nu }_3$ band of ${}^{13}\mathrm{C}_2{\mathrm{H}}_2$ at $1.5\mathrm{\mu }\mathrm{m}$ $\left(194\mathrm{THz}\right)$ . The measurements were made using cavity-enhanced, diode-laser-based saturation spectroscopy. With one laser system stabilized to the $P\left(16\right)$ line and a second laser system stabilized to the line whose frequency was to be determined, a $\mathrm{Cr}:\mathrm{YAG}$ frequency comb was employed to accurately measure the tetrahertz level frequency intervals. The results are compared with recent work from other groups and indicate that these lines would form a basis for a high-quality atlas of reference frequencies for this region of the spectrum.