More on Trebuchets

Two months ago, Rob Koelling posted on a contemporary working trebuchet--a medieval siege weapon which launched projectiles. The current issue of Archaeology contains an interview with Peter Vemming, an archaeologist and medieval weapons expert who is constructing a 22-ton 14th c. trebuchet in southern England this summer.

In Reconstructing Medieval Artillery, Vemming talks about the current popularity of counterweight trebuchets which he calls "simple and reliable technology" and about the experience of creating and operating a full-size model.

Laptop Hazards :: Pain & Loss

While most of us who use laptops love their portability and the way we can use them via wifi all over the Northwest College campus, laptops carry some hazards with them--in particular, injuries and theft.

Two recent articles highlight these problems. CNET News.com's article "Is your laptop a pain in the neck?" reports that repetitive strain injuries, burns, and neck/shoulder problems from laptop use are rising among younger people, leading--sometimes--to serious injuries and disability leaves.

The CNET article urges users to use an ounce of prevention, including the following:

• "The use of peripherals such as docking stations, separate keyboards and mice is probably the easiest way to avoid neck and shoulder trouble. . . . The ideal height of the monitor is about 20 degrees below horizontal eye level, or 8 inches below eye level at a 20 inch viewing distance."
• Special pads and trays can help avoid burns from the bottom of laptops. [Also see Cornell University's "Hot Laptops Cause Problems for Users."]
  
• Repetive injuries can be avoided by "Taking short breaks every 20 to 30 minutes, stretching, eating healthy and exercise."

Cornell University's Ergonomics Web offers useful laptop suggestions at "5 Tips for Using a Laptop Computer." Laptops aren't the only culprits; any computer use can lead to similar health issues. Cornell University also has a terrifically useful article called "Ergonomic Guidelines for Arranging a Computer Workstation-10 Steps for Users."

Ergocise.com offers a page of wrist and arm warm-ups and stretches for keyboard users. I've used many of these same exercises for years to help my overworked, mouse-clicking, right wrist.

The second serious laptop problem is theft, of both administrators' and students' laptops. The Chronicle of Higher Education's Wired Campus Blog reports that a university laptop loaded with 37,000 students' social security numbers and addresses went missing (13May05). A similar event happened at Cleveland State U. , where a stolen laptop contained the social security numbers of 44,000 students (08Jun05).

Besides these campus security problems, campuses all over the country report a rise in the loss of student laptops to theft. To help combat the problem,software companies have created programs such as Computrace and zTrace Gold which help secure and track a stolen laptop computer.