Here is a good looking infographic that will take you on a journey through the history of logo design for some of the leading social networking services. Check out the logo evolution for Facebook, Instagram, Twitter and others from this design.
Here is a useful infographic produced by the website called REtipster which features illustrations of thirty different types of roof. Check out roof types like the A-Frame Roof, the Barrel Vaulted Roof and the Bell Roof by viewing this piece.