Replying to How would you make a clock

For physics i have to make a timing device that can time up to 45 seconds and be accurate to the second.

a quarter of the grade is on how creative it is so ive been racking my brain for cool ways to measure time and so far i haven't got much

ive thought of draining something and having a seconds scale on the side but thats pretty boring and simple

the example that my teacher showed us was a really long tube filled with corn starch except for a little bubble and time was measured by the bubble rising.

anybody got any awesome ideas?