Table: locomotive_registry
Columns: number
name
builder
type
works_number
date

Question: What number has the builder ruston hornsby, the date 1961, and the name Topsy?
SQL: SELECT COUNT("number") FROM locomotive_registry WHERE "builder" = 'ruston hornsby' AND "date" = 1961 AND "name" = 'topsy'

Question: What is the number with the builder hunslet and a works number greater than 822?
SQL: SELECT COUNT("number") FROM locomotive_registry WHERE "builder" = 'hunslet' AND "works_number" > 822