|"Though not a
featherweight machine, the Portable lent itself to travel much better than its Class 3
cousins. It's weight of about 25 pounds must have felt exceptionally portable considering
a full bodied Class 3 could easily weigh in over 50 pounds."
Bergin, Eric Ashman, Seth Gordon, Jeana
Scheirer, Dave Muehling and Andrew Hewitt, "Mechanical Computing."