An example of two Google calendars embedded into one can be viewed at Arnel Dy’s Math Webpage.
The iframe tag and origsrc="domainname.org_############### methods
There is a link in Google Calendar, (Settings > Calendars > yourCalendar > Customize the color, size, and other options) that directs you to Google Embeddable Calendar Helper. Copying and pasting the HTML provided in the Calendar Helper—after configuring the calendar’s settings—on your webpage’s HTML window (click the edit HTML button) will not work even though the preview displays your multiple calendars into one.
Also, copying a part of the HTML code provided at Google Embeddable Calendar Helper and then pasting them after origsrc=" somewhere in the page’s HTML will not work. This method returns an error when I tried this.
What works?
Steegle.com provides the best way to embed multiple calendars in Google Sites. A word of advice: Use Your Keyboard to Copy and Paste the HTML Code.
The title of the article at Steegle.com is: Google Sites - Embed Multiple Calendars (and other things)!
