There has been some debate over whether to judge Sadanobu's efforts in this and related series as mere copying of Hiroshige or as a reworking of his imagery and style to reflect Sadanobu's intimate knowledge of the Kamigata region. Without denying the debt owed to the Edo master, the scholar Matsudaira Susumu believed that other influences included ehon meisho (illustrated books of famous places: 絵本名所) by such Kamigata artists as Takehara Shunchôsai (竹原松朝齋) whose designs often featured written commentaries and a contemplative style similar to many Sadanobu fûkeiga (landscape prints: 風景画). Matsudaira also argued that small-format prints such as the chûban sheets in this series (and especially the even smaller koban and mameban formats in other series) required special skills not only to draw effective scenic views but also to carve and print the designs.*
The name Yotsubashi designated four bridges that once stood at the crossing of the Nagahorigawa (east-west) and Nishi-Yokoborigawa (north-south) Canals. The bridges spanning the Nagahorigawa were called the Sumiyabashi and the Yoshinoyabashi (from the east), while those over the Nishi-Yokoborigawa were called the Kami-Tsunagibashi and Shimo-Tsunagibash (from the north)i. The area was also known for its stores selling tobacco pipes, some of which were purchased as souvenirs from the noted travel spot.
The original wrapper for this series had a more complete title: Naniwa hyakkei meisho shashin kagami (A Mirror of 100 Famous Views of Osaka — Truthfully Copied: 浪花百景名所写真鏡); a fine small-format scene in the manner of Utagawa Hiroshige, depicting the junction where four bridges cross two canals; the yotsubashi were the Sumiya and Yoshinoya bridges over the Nagahori River, and the Kami-Tsunagi and Shimo-tsunagi bridges over the Nishi-Yokobori River; the series was never completed — approximately 63 designs known.
References: HSH, no. 181 (series)*