Levels in ${\mathrm{Si}}^{29}$ were populated with the reaction ${\mathrm{Mg}}^{26}(\ensuremath{\alpha},n){\mathrm{Si}}^{29}$ and subsequent $\ensuremath{\gamma}$ radiation from the various levels was detected with a 37-${\mathrm{cm}}^{3}$ Ge(Li) $\ensuremath{\gamma}$-ray spectrometer. Beginning with the 4.08-MeV level, $\ensuremath{\gamma}$-ray angular distributions (${0}^{\ensuremath{\circ}}\ensuremath{\le}{\ensuremath{\theta}}_{\ensuremath{\gamma}}\ensuremath{\le}{90}^{\ensuremath{\circ}}$) were measured at incident bombarding energies near threshold (${Q}_{0}=0.033$ MeV) for levels with excitation energies between 4.08 and 6.38 MeV. The target was a ${\mathrm{Mg}}^{26}$ metal foil, on the order of 0.5 ${\mathrm{m}\mathrm{g}/\mathrm{c}\mathrm{m}}^{2}$ thickness. Branching ratios and excitation energies of the various levels were deduced from $\ensuremath{\gamma}$-ray pulse-height distributions. $\ensuremath{\gamma}$-ray angular correlations obtained at $\ensuremath{\alpha}$ bombarding energies near threshold were treated as originating from residual nuclei having magnetic quantum numbers $|m|=\frac{1}{2} \mathrm{and} \frac{3}{2}$. Analysis of these angular correlations in terms of level spin and $\ensuremath{\gamma}$-ray multipole mixing was then undertaken. Mean lifetimes (or limits) for these levels were determined using a variant of the Doppler-shift-attenuation method, which involves measurements of the attenuation for two targets of different stopping power. Both ${\mathrm{Mg}}^{26}$ foils and ${\mathrm{Mg}}^{26}$-Au alloy foils (10 at.% ${\mathrm{Mg}}^{26}$ and 90 at.% Au) were used. From these measurements, excitation energies (in keV), level spins, and lifetimes (in fsec) for these levels were deduced; these are, respectively, 4079.5 \ifmmode\pm\else\textpm\fi{} 0.4, $\frac{7}{2}$, 48 \ifmmode\pm\else\textpm\fi{} 8; 4740.5 \ifmmode\pm\else\textpm\fi{} 0.4, $\frac{5}{2} or \frac{9}{2}$, 45 \ifmmode\pm\else\textpm\fi{} 10; 4838.5 \ifmmode\pm\else\textpm\fi{} 0.8, \textonehalf{} or $\frac{3}{2}$, 5; 4894.9 \ifmmode\pm\else\textpm\fi{} 0.6, $\frac{5}{2}$, 10 \ifmmode\pm\else\textpm\fi{} 3; 4932.6 \ifmmode\pm\else\textpm\fi{} 0.4, $\frac{3}{2}$, 10; 5254.1 \ifmmode\pm\else\textpm\fi{} 0.5, $\frac{9}{2}$, 100 \ifmmode\pm\else\textpm\fi{} 20; 5284.4 \ifmmode\pm\else\textpm\fi{} 0.7, $\frac{3}{2} or \frac{7}{2}$, 10; 5651.8 \ifmmode\pm\else\textpm\fi{} 0.7, $\frac{5}{2} or \frac{9}{2}$, 40 \ifmmode\pm\else\textpm\fi{} 15; 5810.7 \ifmmode\pm\else\textpm\fi{} 1.2, $\frac{7}{2}$, 20; 5946.3 \ifmmode\pm\else\textpm\fi{} 3.0, $\frac{3}{2}$, 30; 6106.6 \ifmmode\pm\else\textpm\fi{} 0.6, $\frac{3}{2} or \frac{5}{2}$, 8; 6190.7 \ifmmode\pm\else\textpm\fi{} 1.3, $\frac{3}{2}, \frac{5}{2}, or \frac{7}{2}$, 15; 6378.8 \ifmmode\pm\else\textpm\fi{} 3.0, \textonehalf{} or $\frac{3}{2}$. Excitation energies and lifetimes of levels with ${E}_{x}4.08$ were determined as well. These are (keV, fsec) 1273.1 \ifmmode\pm\else\textpm\fi{} 0.2, 360 \ifmmode\pm\else\textpm\fi{} 70; 2027.6 \ifmmode\pm\else\textpm\fi{} 0.2, 360 \ifmmode\pm\else\textpm\fi{} 70; 2425.0 \ifmmode\pm\else\textpm\fi{} 0.4, 13 \ifmmode\pm\else\textpm\fi{} 3; 3066.9 \ifmmode\pm\else\textpm\fi{} 0.5, 20 \ifmmode\pm\else\textpm\fi{} 7; 3623.1 \ifmmode\pm\else\textpm\fi{} 0.3, 4000 \ifmmode\pm\else\textpm\fi{} 800. These data may be combined with the results of other investigations to arrive at a fairly complete level scheme for ${\mathrm{Si}}^{29}$ in the energy interval $0{E}_{x}$ (MeV) 6.38, including a description of the electromagnetic decay properties. These properties are compared with model predictions of the properties of ${\mathrm{Si}}^{29}$.