During the fifties, when I was in the middle school, we were staying in railway quarters in Bareilly in UP. Our house was just next to the railway station with its front door hardly 15 ft from the railway line.
Naturally all our extra-curricular activities were centered around anything and everything to do with the railways. We used to observe dozens of different types of trains passing in front of our house.
Once a very strong desire arose to test as to what would happen to a coin if we let the train go over it. There it started. One of my playmates got a wild thought- what if the train slips while going over it and crashes?! I did not agree with him , though a doubt persisted in my mind too.
As luck would have it, my cousin from Delhi came to spend time with us. With nothing else to do, we were all set to start with our experiments. In those times, all types of coins were in vogue--round ones, square ones and those with a hole, and those made of copper, nickel or brass.
Now we tried various coins flicked surreptitiously without letting our parents know. After sometime, we became experts in predicting the shape that the coin would take after getting repetitively pounded under the wheels of the train. In some cases the coins got flattened and stuck to the track . With great difficulty we were able to dislodge it. After placing the coin we used to put our ear to the track to try to guess from which side the train would arrive. Since playing near the track was certainly not a safe activity we had to be watchful not to get caught by the elders. Once we placed a heavy duty needle (the type used to to sew quilts). We were thrilled to find that it took the shape of crude knife ! (The next day I overheard my mother inquiring from our domestic help whether she had seen this needle somewhere.)
With the data and the collection of exhibits we could have produced a voluminous research report with the title running something like "Predicting shapes and sizes of various coins when subjected to wheels of various shapes and sizes belonging to goods and passenger trains of Indian Railways". May be our exhibits would have found a place in the railway museum.