This accessory back for mainly studio cameras was patented in 1893 (US 492,025) by Andrew Klay (see below). It was subsequently marketed by Peter Diller out of Bluffington, OH. It is therefore generally known as the Klay-Diller Multiplying Back, even though Diller marketed it as Klay's Multiplying Plate Holder. A small catalog from c.1895, Descriptive Catalogue Klay's Multiplying Plate Holder, has been scanned for this web site.
References:
Wilson's Cyclopaedic Photography, Edward L. Wilson (New York,
NY), copyright 1894, p. 514
Descriptive Catalogue Klay's Multiplying Plate Holder, Klay's Plate
Holder Co. (Bluffington, OH), undated c.1895
American Annual of Photography and Photographic Times
Almanac for 1898,
The Scovill & Adams Co. (New York, NY), ads p.
43
The
International Annual of Anthony's Photographic Bulletin, Vol. XII for
1900, E. & H.T. Anthony & Co. (New York, NY), copyright 1900, ads,
p.6 (Peter Diller) and
p. 52
(Hyatt)
Catalogue No. IIII of Professional and Amateur Photographer's
Supplies, Wm. F. Uhlman (St. Joseph, MO), c.1901, p. 32