RICHMOND, Va.—A state conservator in Virginia began the delicate task Wednesday of trying to open a 134-year-old time capsule that had sat beneath a towering a statue of Confederate Gen. Robert E. Lee in Richmond. Chelsea Blake, a conservator with Virginia’s Department of Historic Resources, pressed a vibrating tool with a hard metal tip against the rectangular capsule about the size of a large shoebox, covered in various tones of brown and green. Opening the capsule has so far proven to be a challenging—and time-consuming—task. As of early Wednesday afternoon, Blake was still sitting at a table with her gloved hands working various tools along the capsule’s edges. The container was made of lead, which was heavily corroded, not the copper that state officials had expected. The capsule was also partly covered in mortar, which must be gingerly chipped away while trying to preserve as much as they can. Both …