Setting "tk scaling" in Tkinter affects widgets but not text

I'm trying to use Tk's "tk scaling" feature to zoom a GUI but it only seems to change the size of the widgets, not the text. Is it possible to use "tk scaling" with Tkinter and have it work appropriately? Here's my test script:

#!/usr/bin/python

from Tkinter import *

root = Tk()
root.tk.call('tk', 'scaling', '-displayof', '.', 50)
root.geometry('640x480+0+0')
label = Label(root, text='THis is some text')
button = Button(root, text='my button', command=root.quit)
la开发者_开发知识库bel.pack()
button.pack()
root.mainloop()