 Rabbi Henkin felt that in a case where tuna are being caught, it is halachically permissible to check only a few of each batch and not each individual fish; Rabbi Feinstein, on the other hand, felt that each fish needed to be checked for kosher markings that it was in fact, a tuna and not some other fish.In 1936, Rabbi Henkin declared that Rabbi Yehoshua Seigel's 1905 Manhattan eruv could no longer be relied on because he had only acquired permission for ten years.However, Rabbi Henkin's main argument why the eruv could no longer be relied on was because of the construction of bridges that crossed Manhattan’s waterfront (Luach HaYovel Shel Ezras Torah, p. 62).