The pilot of the Cessna 172S was practicing touch-and-go landings on runway 21, a 6,001-foot-long, 150-foot-wide, asphalt runway. He reported that he flared high and added additional engine power to smooth the touchdown; however, the airplane landed hard and bounced. He performed a go-around and subsequently landed without further incident. Subsequent inspection of the airplane revealed damage to the nose gear assembly and engine firewall. Winds reported at the airport about the time of the accident, were from 200 degrees at 11 knots, gusting to 17 knots. The pilot did not report any mechanical failures or malfunctions of the airplane.