"The Doings of the Van Loons" by Fred I. Leipziger
They were collected in a book:
1912 Series - Ball Publishing, 1912, coverprice none , 72 pages.
Format: 5-21/32" tall x 15-19/32" wide; hardcover; b&w cover & interior; cover overlaps interior by 1/4"
Fred I. Leipziger (Pencils) Fred I. Leipziger (Inks) typeset (Letters)
Note that he went by "Leipziger" rather than "Leipzig". HERE
is an ebay link with scans. You might want to archive these to your hard drive (right click and "save picture"), since ebay listings expire after a few months. HERE
is a sample panel from the Cartoon Research Library at OSU. Their catalog entry says it came from the Louisville Courier Journal in 1913.
The strip ran in the LA Times from 6/14/1914-12/31/1916. Note that the Times is digitized in the ProQuest Historical Newspapers database, so if you have access to a local research library (like a university, or perhaps the NY Public Library), you might be able to see a run of them. THIS PAGE
has a few of the strips trimmed from newspapers and for sale. It indicates that the strip ran from 1913 to 1925.