Did this work in earlier version of Postgres?

I could have swore that this worked in earlier releases of Postgresql
i.e. 7.4.

CREATE TABLE public.test
(
junk double NOT NULL,
CONSTRAINT junk_pkey PRIMARY KEY (junk)
)WITHOUT OIDS;

Now it gives a error that type double does not exist.

During the summer of 2004 I ported a large Firebird database to 7.x and
firebird uses the term double which in PG is a float8 I believe.
Anyway i was able to just paste the Firebird ddl in to the query editor
and the server would substitute the correct PG native type.

varchar works, how come double does not?

Thanks,

Tony