Editor's note: A collector who wishes to be called "The Rhino" has agreed to answer questions sent in by readers. If you want to know more about an insulator related topic, write Crown Jewels or send an email to: editor@cjow.com                                                                               
                                                                 

Question: "I have an insulator which says Patented May 2 1893 Hemingray No 40. But I don't see anything that says CD. Should that be printed on it some place? I do not understand the CD bit. Thanks."

Rhino's Answer: "CD" stands for "Consolidated Design". Creating a reference guide based on "consolidated designs" was the brainchild of N R Woodward many years ago. It is a reference designed for insulator collectors, and did not exist at the time most insulators were manufactured. Therefore, you will not find CD numbers embossed on insulators.

Each style, or shape, of insulator has been given a CD number. About 350 CD numbers have been assigned to threaded, pin-style insulators manufactured in North America. In some styles, only one company made a particular shape. But some styles of insulators were manufactured by many companies.

Your Hemingray #40 is one of those styles. The shape is referenced as a CD 152. These were manufactured by a half dozen companies. CD 152's can be found embossed with the letter "B", the name "Brookfield", "California" (shown below), with a "diamond", "Hemingray", and "McLaughlin". They are also found embossed only with numbers: "No 40", "No 48", and with no embossing at all.

The embossing on Hemingray 40's is worded about ten different ways. Overall, Hemingray 40's are among the most common insulators ever manufactured, and were used by the hundreds-of-thousands when long-distance telephone lines were being constructed in the time period ranging from 1915 to 1925. A different shape, manufactured by Hemingray as the #42 (CD 154) replaced the #40 style by the mid-1920's.

Hemingray 40's in aqua are worth a buck or less. But they are also found in more desirable colors: yellow green, olive amber, jade aqua, and milky aqua. California CD 152's are found in purple, peach, yellow, and two tone purple and sage green. Among the most valuable CD 152's are the McLaughlin's, of which only a small number of examples have been found.

The Rhino