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_name_10 (number VARCHAR, name VARCHAR, builder VARCHAR, date VARCHAR)

### Question ###
What number has the builder ruston hornsby, the date 1961, and the name Topsy?

### Accurate SQL ###

SELECT COUNT(number) FROM table_name_10 WHERE builder = "ruston hornsby" AND date = 1961 AND name = "topsy"