Using the spectroscopic capabilities of a scanning tunneling microscope, we identified and investigated a low-temperature reconstruction pathway for forming Si(111)($\sqrt{3}$\ifmmode\times\else\texttimes\fi{}$\sqrt{3}$)R30\ifmmode^\circ\else\textdegree\fi{}-Ag from the Si(111)3\ifmmode\times\else\texttimes\fi{}1-Ag interface. A metastable intermediate phase consisting of one-dimensional atom chains atop the Si(111)3\ifmmode\times\else\texttimes\fi{}1-Ag reconstruction stabilizes locally. The density of states at the chains indicates a Ag-Si bonding configuration similar to that of the ($\sqrt{3}$\ifmmode\times\else\texttimes\fi{}$\sqrt{3}$)R30\ifmmode^\circ\else\textdegree\fi{} reconstruction. We propose a mechanism for the (3\ifmmode\times\else\texttimes\fi{}1) to ($\sqrt{3}$\ifmmode\times\else\texttimes\fi{}$\sqrt{3}$)R30\ifmmode^\circ\else\textdegree\fi{} phase transformation at low temperature. \textcopyright{} 1996 The American Physical Society.