how to subscribe to this calendar

One can easily configure many different applications (Google Calendar, Apple's iCal, Mozilla Sunbird, KOrganizer, Microsoft Outlook, BlackBerry Calendar, etc.) to automatically show the seminar schedule. You just need to subscribe to the iCalendar feed http://www.google.com/calendar/ical/bowdoinmain@gmail.com/public/basic.ics in your favorite calendar.

Google Calendar: Sign in to Google Calendar using your own account. In the 'Other calendars' box, click 'Add' and 'Add a friend's calendar.' Enter 'bowdoinmath@gmail.com' in the box which pops up.
more help on Google Calendar

iCal on Mac OS X: Create a new calendar in iCal. Command click on the newly created calendar and pick 'Subscribe.' Enter the address http://www.google.com/calendar/ical/bowdoinmath@gmail.com/public/basic.ics and click 'Subscribe.'