The need to install QuickTime became obvious when I did the search. It was a free plug-in and took about 7 or 8 minutes to complete. It's affiliated with I-Tunes and an adjustment had to be made with that application. After installation, I shut down Firefox; after going back online, the Berks Co., PA, Deeds search worked.
Berks County uses the Russell Index which is described in greater detail here.
From the Berks County, PA, Recorder's site:I have used easier systems online; however the index online starts with the year 1752, and that's a plus.
These books are compiled in the Russell Index System which groups the names by consonants LMNRT contained in the name. Be sure to page through the entire section and scroll down the entire page and also look for similar names under different spellings. If you have used the physical copy of the Russell Index books in our office you will find this digital version much easier and faster to use.