how to obtain the following output from a single table

Table Name: Employee
S_No    Heading  Summary
 1       a         A
 2       b         B
 3       c         C
 4       d         D

I want to display it as:

S_No  Heading  Summary   S_No1  Heading  Summary2
1       a        A         2       b         B
3       c        C         4       d         D