So what was the best thing before sliced bread?

Tweet

I gather that the phrase "The best thing since sliced bread" was coined at the end of World War II, when sliced bread once again became available after the process had been discontinued during the war for reasons of economy. The first ready-sliced loaf had been sold in 1928 and the concept immediately became highly popular. So what was the best thing before sliced bread was sold? Did people describe something as "the best thing since the penny-farthing bicycle" perhaps? It seems unlikely!