Horizontal.

SELECT * FROM gallery2 WHERE topic_id="585675" UNION SELECT * FROM gallery2 WHERE topic_id="995552" UNION SELECT * FROM gallery2 WHERE topic_id="1707023" UNION SELECT * FROM gallery2 WHERE topic_id="1318503" UNION SELECT * FROM gallery2 WHERE topic_id="58111" UNION SELECT * FROM gallery2 WHERE topic_id="1543997" UNION SELECT * FROM gallery2 WHERE topic_id="1386162" UNION SELECT * FROM gallery2 WHERE topic_id="889958" UNION SELECT * FROM gallery2 WHERE topic_id="373940" UNION SELECT * FROM gallery2 WHERE topic_id="1471789" UNION SELECT * FROM gallery2 WHERE topic_id="1243338" UNION SELECT * FROM gallery2 WHERE topic_id="1771146" UNION SELECT * FROM gallery2 WHERE topic_id="936326" UNION SELECT * FROM gallery2 WHERE topic_id="258072" UNION SELECT * FROM gallery2 WHERE topic_id="129321" UNION SELECT * FROM gallery2 WHERE topic_id="717201"