Drawings à la Ferdinand Petrie - I

I've had a book around for a while and I decided to "reproduce" the demos in the book as exercises. The book is: "Drawing Landscapes in Pencil" by Ferdinand Petrie.  

Here are my first three drawings and a closeup view on the last one.

Two things that can easily be observed here are that: the strongest contrast in value (light and dark) is at the focal point. If you want the lightest area to pop out, surround it with the darkest area (and vise versa). In addition to that, the superposition of shape with different values adds depth to the picture.

As you can see in the closeup of the last picture, it's all done with small pencil marks. Compared to a brush with paint, this is a slow process...