Around the turn of the century, Waltham adapted two of its popular models to the Swiss bridge style. This style was reserved for the top American Grade. The models used were the 12 size 1894 model and the 16 size 1899 model.
Apparently the E. Howard Watch and Clock Co. contracted with Waltham to produce the 16 size model as a new watch to replace the Series XI and XII. Some watches appear with the full markings of the E. Howard Watch and Clock Co. The brochure from 1903 that was produced by Hayden W. Wheeler shows these early examples and remarks on the "merger" of E. Howard and Co. with the E. Howard Watch Co.
Later examples designed and produced by the E. Howard Watch Co. have a distinctive bridge design and a much different overall construction.
There are also transition pieces that have E. Howard Watch Co. markings on the Waltham design and there is an intermediate bridge design that has the standard Waltham style center bridge with the straight design supplemental bridges found on early E. Howard Watch Co. examples.
The ultimate example of these bridge style watches is the Edward Howard model produced as the E. Howard Watch Company's ultimate prestige watch to compete with the Premier Maximus watch from Waltham.