new fuel pump - glass bowl?

Just bought a new single-action glass bowl fuel pump like this one. http://walcks4wd.com/fuel-pump-glass-bowl-no-vacuum.html
It looks to me like the glass bowl goes on top, based on the shape and the way it mates to the engine. My question is: what purpose does the glass bowl serve? It seems like it would be a sediment basin which would collect dirt and such, in which case seems like it should go on the bottom. Is it just so you can see the fuel going through?

 

It is a filter. There is a screen on the bottom of the bowl that keeps the bigger junk from getting to the carb. It's not that bad of a setup. My '49 came through the factory with that type of pump and the carb has been just fine.

 

It can be pretty handy to observe the glass bowl when diagnosing problems. Water or dirt in the fuel are visible, or air leaks, fuel line blockages, lack of fuel, etc.

 

X2!

I once heard: back in the day, fuel quality was less certain/regulate and this allowed for a visual inspection of what you had bought.