[Pharo-project] How can I change the size of the World ?

Hi folks. Actually, I a not sure if what I want is to change the size of the World, but the size of the windows. The problem is this: the PharoCore images, when I open them, they have a little size by default. I always need to make them bigger. I have to do the same with the Dev images. So, I would like to do that from Smalltalk side and add it to my scripts to build dev images. Is this possible ? how ? I looked in Display and World, but I didn't find what I need. Cheers Mariano