Excavation characteristics in relation to rock hardness and strength

Ground Engineering's iPad edition

Ground Engineering is the leading magazine for the UK geotechnics industry providing information on new and practical aspects of geotechnics, engineering geology and geo-environmental engineering.
If you have an iPad, you can now read Ground Engineering magazine for free! GE Magazine is one of the industry's most respected trade publications, affiliated with the UK's New Civil Engineer organization. The app is made available thanks to sponsorship from Allu. I've tried it out, and the format is excellent, the text is easy on the eyes, the figures are out of the way, but accessible with just a tap. Even the advertisements are nice, partially interactive but not over the top. Although they call it an app, it shows up on your bookshelf app.

http://www.geoprac.net/geonews-mainmenu-63/61-available-resources/1208-ground-engineerings-ipad-edition-is-now-live
http://itunes.apple.com/gb/app/ground-engineering-ge/id526030700?mt=8&ls=1