Volunteers from the Valverde Battery, 12th Texas Artillery, and members of the Vicksburg National Military Park’s Living History Group will continue artillery demonstrations at 10:30 and 11:30 a.m. today at Fort Garrott, Stop 14, on the South Loop. Also today, Pemberton’s Headquarters on Crawford Street is open for tours with the price of admission to the park, and rangers will give walking tours of the historic area.