By splitting into two trials is burnt at a temperature of 600 shells, 650, 700 and 750 degrees Celsius for 5-hour firing shell and oysters at a temperature of 600° c. 3, 5, 7, and 9 hours.
It was divided into two by firing shells at a temperature of 600, 650, 700 and 750 degrees - C for 5 hours and burnt oyster shells at 600 ° C for 3, 5, 7 and 9 hours.