May 2002 Robertsons Patent Battery Insulator

The two battery insulators showcased on this month's magazine cover and in this article, along with a third specimen, were dug approximately two years ago from an outhouse pit in St. Paul, Minnesota. Shortly thereafter, a listing for an "old threadless insulator" appeared on eBay. The text described the insulator as a rare unknown type and the accompanying photo pictured an odd mushroom shaped aqua glass object with what appeared to be a threadless pinhole.

COVER: The photos on the cover were taken by Dwayne Anthony who shares the story of the Robertson's Patent Battery Insulator beginning on page 17 of this issue.

On the top left, the large pinhole variation is pictured next to the smaller pinhole type to the right. In the middle you find a picture taken from the base looking into the pinhole of the each of the battery rests.

The flat top battery rest was described as "an odd mushroom shaped aqua glass object with what appeared to be a threadless pinhole."

Even though I couldn't quite put my finger on it, there was something vaguely familiar about the peculiar design of this object. Staring at the photo I immediately began the often-frustrating process of recollecting elapsed data from the deepest nodes of the memory banks. Then the mental revelation suddenly came to view! I recalled a visit to the home of good friend and collector, Dario Dimare, back during the Marlborough National Show in 1995. While looking through an early L.G. Tillotson catalog from his extensive library, Dario had pointed out an ad for a bizarre shaped battery insulator. At the time, a larger mushroom shaped threadless insulator with a reconstructed top, embossed M. T. Co., had been assigned a new threadless CD number. Dario was commenting on the general similarity of the M. T. Co. and the battery insulator in the ad. It was this recollection of the rough rendering in the Tillotson ad, depicting a flat topped mushroom shaped insulator, that prompted me to pursue the eBay insulator further. (FYI: the M.T. Co. "threadless" was later reassigned a new CD number under the battery insulator classification: CD 61.)

Armed with the notion that it could possibly be a unique early telegraph era battery insulator, the figurative dice were tossed with a bid submission. Soon to follow were the typical withdrawal pains of wishing a higher bid had been submitted, as I helplessly watched it close to a higher bidder within the final seconds of the auction.

Undaunted by the acquisition loss, I just had to investigate further. Contact was made with the seller to prod for any clues that may assist in identifying its heritage. A final note was added to the email message: "If you happen upon another, I am interested."

Within hours the exciting news appeared in his reply -- he had a second specimen! Negotiations then ensued and the second example was procured. During the closing of the deal it was mentioned that a third specimen was also found, but had some rather major damage to the "skirt" area. In the description of this third specimen it was noted that it had a much larger pinhole than the other two. Negotiations were again quickly placed into motion and the third example was eventually acquired as well.

During further communications with the seller, who was one of three diggers involved in the discovery of the three insulators, the following information was given: "We obtained access to an older area of St. Paul on the old Stillwater Road Stagecoach Line. This road also had a telegraph line installed about 1855 and it seems some of the insulators went into the local privies. There was a listing in an old 1860 city directory for a telegraph operator and office in the area of the dig. In addition to the battery insulators, we've found assorted broken CD 718's, 732's and one unknown style. We've also found quite a few historical flasks and some early blob sodas, plus pontiled pickles and sauces."

These insulators were indeed from an early site. The seller also provided a portion of an insulator that was found in the same outhouse hole; it was a gorgeous forest green CD 718 threadless! Immediately upon acquiring the two specimens, an email was sent to Dario requesting a copy of the ad. On a whim, I also contacted Elton Gish to see if he had by any chance run across such an insulator in his extensive library of patents. It was a pleasant surprise to hear that he did indeed have patent information on a battery insulator that very much matched my description of a "mushroom shaped threadless insulator" and it would be in the mail pronto! Once the patent office copies arrived, there was little doubt that the insulators matched patent No. 105,252, issued on July 12, 1870 for a battery insulator designed by O. W. Robertson. The 1872 Tillotson ad arrived a short time thereafter, illustrating a battery insulator by Robertson, which further solidified the similarity!

Studying the patent drawing and accompanying specifications, this insulator was specifically designed for mounting on a threadless pin, which in turn was mounted on a table. When comparing the patent drawing with the Tillotson ad drawing, you will note some slight design deviations, primarily in the "cap" rim projections. This is also apparent when comparing the patent drawing with the actual specimens. It is not an unusual occurrence to see minor design alterations in a final manufactured product. In some cases this was due to modifications required by the mold makers and manufacturers. The most interesting and puzzling modification is the one found on the specimen with the larger inner skirt opening. Was this a feature intended for a different mounting application, or possibly a later design improvement?

Another interesting bit of relevant information is found with Robertson's city of residence, versus the location in which the insulators were found. The inventor, Orris W. Robertson, was a resident of Milwaukee, Wisconsin, at the time the patent was issued. The insulators were found in St. Paul, Minnesota, just a mere 300 miles from Milwaukee. Maybe Robertson canvassed the local cities in his region, visiting telegraph offices to promote his wares, even possibly leaving samples behind?

In summation, and from all the evidence gleaned, these battery insulators are of early 1870s vintage and were probably discarded in the mid to late 1870s. Based on their rarity, it is unlikely that they saw widespread usage. One additional specimen with the larger interior opening has been confirmed and appears to have come from a different source. So, of the four reported specimens, two are designed to accept a standard threadless pin, per the original patent design: the other two contain the larger "non pin" open inner skirt. Original cost in the Tillotson catalog was 30 cents each. Dimensions are: 3-1/4 H x 3-1/2 W. The manufacturer is currently unknown. A CD num-