In 1924 tracks were mostly either grass, sand, or ground cinders (which I and ever runner I ever knew called "clay," which is what I'm going to call them from now on), and runners competed without starting blocks. The 1924 Olympics in Paris took place in the Olympic Stadium at Colombes, which featured a clay track. The ubiquitous all-weather polymer tracks of today's athletic competitions were not invented until the 1960s. The first widespread polyurethane track, 3M's "Tartan Track," which is still widely popular today, was not used at an Olympic competition until 1968, during the Olympics in Mexico City. Experiments in rubber tracks and even asphalt tracks predate the Tartan Track, but anyone who's ever run on those tracks--and I've had the unpleasant experience of running on both, and training for most of my 400 career on rubber--knows that they're really awful and don't take well to spikes anyway. Clay tracks do not provide as resilient a surface as polyurethane, and particularly on the start they don't give very good traction. Furthermore, starting blocks were not invented until 1929, and truly portable ones weren't invented until even later. Prior to 1929 sprinters and mid-distance runners either up-started or down-started without blocks. Grass tracks were (and are) usually harder than sand or clay tracks, and usually runners would simply down-start without the benefit of any aids at all. Clay tracks were easier to manipulate, so runners either brought their own trowels or were distributed them (at major competitions), in order to dig out pits for their feet to rest in during a down-start. Indeed, the great George Simpson has never been officially credited for breaking the 100m world record in 1929 (during the first leg of the 100 double during the NCAA Championships) because he used starting blocks, which had not yet been approved by the IAAF. The ubiquitous use of all-weather materials for outdoor tracks (usually Mondotrack these days at the international level, including at the Rio Olympics) has precluded runner's need for and ability to dig out their starting pits--I challenge you to try to tunnel your way through a polyurethane track, go ahead try it, I'll wait right here--but even shortly after the 1924 Olympics the introduction of starting blocks had already made the old method obsolete. Starting blocks do not damage the track as much, and are much more regular.