You never know, you know… ?

by Dan Wiswell

As a collector of antique test equipment, I have visited many antique shops over the years with the hope of stumbling upon something good. A few decades ago, there were plenty of examples of high-quality antique instruments for sale in a variety of after markets. Today it is fairly unusual for me to find something that I’d like to own. I’ve been reminded at home recently that I really don’t need more than twenty-seven megohmmeters. But, every so often…

Kellogg Model 1917

Years ago, I was on Cape Cod and decided to stop at an antiques and collectables shop. My eyes were immediately drawn to the device pictured below.

It is a WWI era field telephone/telegraph, made by the Kellogg Switchboard and Supply Company in Chicago, Illinois. The person behind the counter would not negotiate on price in spite of showing him that the hand-crank assembly needed repair. I left the store without it. Three years later I returned and found it again, but this time it was tucked away and on display backwards in a corner of the showroom. The proprietor gave it to me for almost half off the asking price.

It didn’t take much to reseat the hand-crank assembly. Now, if you happen to be holding onto the output while the crank is turning, you’ll receive a quick lesson on the meaning of ringing out a circuit. In the pictures you can see that besides the telephone handset there is also a telegraph key. A schematic and a screwdriver are housed inside the top cover. The schematic shows auxiliary condensers (capacitors) used to integrate this unit into a larger telecommunications network. There are many references and pictures online that show equipment like this being used in various wars during the nineteenth and early twentieth centuries. Finding this device in such good condition was an absolute bonus to me. Not only was its original leather strap in place, its conveniently placed screwdriver was there too. These accessories are typically the first bits of ephemera that get separated from kit of this sort. While researching this piece prior to writing about it, I was surprised to find that the next serial number down from this specific unit is currently for sale on Ebay, minus its own screwdriver. I’m tempted to buy it so that I can give myself a call.

The Kellogg Switchboard and Supply Company was founded in 1897 by Milo Kellogg. In 1897, Alexander Graham Bell’s patent for the telephone expired, which allowed Mr. Kellogg to expand his product line to include a variety of wall-mount and portable telephones. Prior to this, the company offered telephone switchboards designed to handle large amounts of incoming and outgoing telegraphic signal traffic. As a supplier of equipment to the U.S. military, many thousands of Models 1917 were manufactured during WWI. A poling of serial numbers for surviving units listed on various websites show that more than thirty-six hundred units were manufactured between March and June of 1918. ITT Corporation purchased controlling interests in the company in 1952, after which Kellogg ITT morphed into a number of modern telecommunications entities. The company now exists as Cortelco, based in Corinth Mississippi.

Troemner Apothecary Balance

As I’ve said, sometimes you just never know when you’ll happen upon something that will catch your eye. In 2006 I was cruising up the coast of New England with a group of boaters from our home port of Salem, Massachusetts. On the first leg of our journey we went from Salem, passed Cape Ann, and stopped for the night in Portsmouth, New Hampshire. The next morning there was a flea market within walking distance of the place we had docked for the night, so my wife and I stopped in to take a look around. I could not believe the improbability of finding a working Troemner apothecary balance, possibly made before the beginning of the twentieth century.

Henry Troemner and his products were well regarded in his time. The discovery of gold in California during 1848 was a tremendous boon to his company. Along with many thousands of commercial balances and scales, the Troemner company also made gold bullion balances and scales for the United States mint in Philadelphia, the San Francisco mint, and the Department of Treasury. The unit pictured below is an example of a high-quality instrument that has maintained its accuracy for more than one hundred years after it was made. I can’t actually ascribe a date to this particular unit. The only internal clues I can find are recorded in pencil under the top panel. Inside, the inscription reads: “F. Greiss, Maker, Phila. PA.” Company history files show that Henry Troemner began making scales and balances with a partner in Philadelphia, PA in 1840. He began making them under his own name in 1844. What have I actually uncovered here? The label on the outside of the case says “Henry Troemner, Marker, Philadelphia, PA.” Was F. Greiss an original partner in what became the modern Troemner company? If so, that would push my estimates of the age of this balance by a few decades.

I have seen similar beam and armature assemblies inside much older Troemner balances than what my first estimates of the age of this specimen was. My best guess before I opened it up had been somewhere between 1895 and 1905. But now? It may be significantly older. By 1910 the company was using labels that show model and serial numbers on their products. I will have to keep searching for clues to put a finer point on a date for this piece. Any help from the outside world would be greatly appreciated.

Visibility and Light Meters

There was another time when knowing a bit more about what a seller had than they did, paid off well for me. The person that I bought the instrument depicted below from thought it was some kind of picture viewing device that no longer worked.

It is actually a Visibility Meter designed by Matthew Luckiesh and Frank Moss, both of whom worked together in the 1930s when Mr. Luckiesh was the director of General Electric’s Lighting Research Laboratory located in East Cleveland, Ohio. This device uses Neutral Density (ND) filters that are manually adjusted until an image or task is no longer visible. The observer then looks at the adjustable scale on the side of the instrument to determine the approximate light level recommended to properly illuminate a particular scene. This specific unit was manufactured in one of the first production runs, as its case has PAT.APPL.FOR. embossed on the lower left, front side of the instrument. That would put an approximate date of manufacture for this device at about 1935-1936. While we are on the subject of light measurement, let’s dive a little deeper.

Illumination as a field of study has been with us for centuries. In ancient times, strategically placed light houses positioned along the world’s coastlines have saved countless lives and the fortunes of many. The foot-candle is a parameter that was originally powered by whale oil. Measuring light with any degree of repeatable accuracy is a much more recent innovation. In the 1870s, the light sensitive properties of selenium were discovered, which paved the way for the development of modern photocells. This discovery happened at a very fortuitous time as the world was on the edge of electrical illumination. Light meters using selenium-based photocells became available to the general public in the 1930s with the development of products like the Weston Model 603.

Notice that the photocells of this unit are green. They were designed to have their best frequency response at 550 nm (nano-meters). This coincides with the typical frequency response of the human eye which is centered in the green region of the visible light spectrum. Unfortunately, these photocells were very fragile and often small amounts of air entering into the photocell’s structure will cause them to oxidize and lose their original color. They also generally deteriorate with age. Of the Weston Model 603s in my collection, all of them still measure light, but those with non-oxidized, green photocells exhibit the best frequency response and sensitivity.

Many people ask how old a piece of equipment is when I show them something of particular interest. Often, people also want to know how different parameters were measured prior to the advent of the various display technologies in use today, or before software became ubiquitous for that matter. This is a subject that has always fascinated me. My opinion on which of my instruments is my “favorite” has changed many times over the years. A strong contender has always been this Weston direct-reading Ohmmeter made in 1921.

I think what draws me to this unit is that its range-changing brass peg is still with the unit. By connecting it to an old-fashioned dry-cell battery, it still measures resistance across all three of its ranges accurately. When I open a piece of equipment for the first time, whether for repair, restoration, or for research, I am continuously surprised and often humbled by the innovations that were created in what we now refer to as “the days of old.” The people designing and using these instruments back then were truly advancing the state of our art.

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Dan Wiswell (dcwiswell@aol.com), is a self-described Philosopher of Metrology and President/CEO of Amblyonix Industrial Instrument Company in North Billerica, Massachusetts.