Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_25740548_2 (original_air_date VARCHAR, directed_by VARCHAR)

### Question ###
How many episodes were directed by Tim Matheson?

### Accurate SQL ###

SELECT COUNT(original_air_date) FROM table_25740548_2 WHERE directed_by = "Tim Matheson"