Read Carefully and Identify the Correct Relationship:
 
1. Assertion (A): Hourglasses became useful because they could measure fixed intervals of time without using water.

Reason (R): Hourglasses work because fine sand flows steadily from one bulb to another through a narrow opening.
 
2. Assertion (A): The world's largest stone sundial is located in Jaipur.

Reason (R): It measures local solar time, whereas Indian Standard Time requires correction.