Comments:

I rate this sundial the maximum 5 stars, because it's the best one that I've found and tested. Best in terms of accuracy and solidity.

This 16-inch diameter brass armillary sundial is solidly-constructed, beautiful, and it passes my accuracy-test. I expect a sundial to be accurate within 5 minutes. This brass armillary is the only sundial I've bought that hasn't failed that test. I must admit, however,that I've only tested it once, at one afternoon time of day.

I've bought a number of sundials on the Internet. This is the one that I recommend, if your budget permits this large, heavily-constructed brass sundial.

If your budget doesn't allow this sundial, then at least choose an armillary sundial. When shopping on the Internet, armillaries are the most reliably-accurate sundials.

Where to use it? If you have a table or bookcase near an east, south or west window, you could set it there as a window-sundail. But its large size makes it fully suitable as an outdoor sundial for garden, yard, patio, etc.

From what I've read in books on sundials, brass is fully weather-proof, and, if anything, will eventually merely acquire an attractive antique-looking patina. This sundial is quite solidly-constructed.

An armillary sundial is a type of ring-equatorial sundial. They consist of several metal rings, for structural strength and convenience. One nice thing about this sundial is that, unlike many armillaries, the meridian circle and the hour-band aren't full circles, and so the meridian band wont't shade the hour reading around noon; and the upper (southern) side of the hour band is less likely to shade the hour reading, even on the day of the equinox. With other armillaries, when those things occur, they can be dealt with, and aren't a serious problem. But with this armillary, those problems don't even occur.

In the event that, early or late in the day, the hour band does shade itself, that won't prevent a reading, except on the actual day of equinox. On other dates, there will be a sliver of illuminated hour band, and a shadow-reading available there, along upper or lower edge of the hour band.

I should say something about pointing the arrow at the right altitude: The sundial's mounting base is useful if 1) you're using it for indoor display; or 2) You live at about 44 or 45 degrees latitude (north or south). Otherwise, set the sundial up without the base. If you live at around 44 or 45 degrees latitude, just set the sundial up, on its mounting-base, facing north (or south, if you live in the southern hemisphere).

If you live at a different latutude, then here are some instructions for set-up. it isn't difficult:

Measure the length of the shadow-casting arrow, from tip to the middle of its base. My measurement, for this sundial, was 25 and 5/16 inches. Call this distance "L". Write "L = " followed by that distance. So, for this sundial, L = 25 and 5/16 inches.

Now, find the sine of your latitude. A scientific calculator, nowadays, is the easiest way, and the usual way to find that sine. With many or most scientifics, you just enter your latitude, and then press the "sine" key. With some scientifics, you instead press the "sine" key first, and then your latutude. Or, alternatively, you could instead look up the sine of your latitude in a table of sines.

Multiply L by the sine of your latitude. Call that "H". Write "H =", followed by the result of the multiplication.

L stands for length. H stands for height.

Now, using some sort of supports, maybe a wooden mounting block of your own construction, mount the sundial so that you get the following measurements:

Using a retractable tape meassure, measure the height above the ground of the tip of the arrow. And measure the height above the ground of the middle of the base of the arrow. The difference between those two heights should equal H.

So, try different tip-positions for the sundial, till you find one at which the difference betweent thow two heights, at the ends of the arrow, equals H.

One more tip: If you're going to use a compass to point the arrow northward (southward in the southern hemispher), then be sure to account for "magnetic variation" I(sometimes called 'magnetic declination"). Say, for instance, that the magnetic variation in your area is 10 degrees east. Then you want to turn your compass so that it's reading 10 degrees east of magnetic north. Then the compass will be pointing true north.

Another way of pointing the sundial north would be to find the time at which the sundial should read (say) 12 or 3 p.m, etc. And then turn the sundial till it reads that time (making sure that you've got it tipped correctly).

How do you find that time? That amounts to converting clock time to sundial time. That isn't difficult, because, it's just the reverse of converting sundial time to clock time. There is a table, found in sundial books, and some encyclopedias and astronomy books, called the "equation of time". Usually, to get clock time, you add the equation of time to the sundial's time. That equation of time is called "mean minus apparent".In some navigational sources, however, they give the equation of time in such a way that you must instead _subtract_ it from the sundial time to get the clock time. That equation of time is called "apparent minus mean".

But you must add one other thing: Your longitude-correcton. Find your longitude, from a map, or from the Internet. And find out the longitude of your time-zone's standard meridian. Each time zone typically has a standard meridian whose number of degrees is a multiple of 15. For instance, for the U.S. eastern time zone, the standard meridian is at 75 degrees west. Central is 90 degrees. Mountain is 105 degrees. Pacific is 120 degrees. As you can see, each is 15 degrees more than the previous one. In England, it's zero degrees. In Western Continental Europe, and mush of Eastern Europe too, it's 15 degrees east.

Now, if your longitude is west, as it is in the Americas, then subtract the longitude of your time-zone's standard from your own longitude. The result will be positive or negative, depending on where you live in your time-zone. Multiply the result by four. That gives your longitude correction.

If your longitude is east rather than west, as it is in Continental Europe or Australia, then you, instead, subtract your longitude from your the longitude of your time-zone's standard meridian. (the opposite of what you do when your longitude is west).

Now, add your longitude correction to the equation of time, for the date on which you're reading the sundial. That sum is what you must add to the sundial's time, in order to get clock time. I'll call that your "complete correction"

But, if you're using a navigational source, that gives apparent minus mean, instead of mean minus apparent, then you subtract that equation of time from your longitude correction, to get the complete correction, the amount that you add to your sundial time to get clock time.

Now, let me return to the ways of pointing the sundial's arrow north:

As I described earlier, could use a compass. Or you could do the following:

Chose a sundial time at which you want to do the sundial's north (or south, in the southern hemisphere) alighment. I suggest 12 as the best sundial time for that purpose, but any will do. For instance, 3 p.m.? Fine.

Find the complete correction, as described above. Subtract it from the sundial time at which you want to set up the sundial. That gives you the clock time at which you should do the alignment. Turn the sundial so that is reads the sundial time that you've chosen to use.

I like that method, but the compass method is fine too. Use whichever one you prefer.

By the way, most scientific calculators expect an angle to be in decimal degrees. That means that your latitude will have a decimal fraction. For instance: 41.37 degrees.

But many sources will, instead, give your latitude in degrees, minutes and seconds. If it's given that way, then do the following:

Divide the seconds by 60, and add the result to the minutes, to get decimal minutes. Divide that decimal minutes by 60 to get decimal degrees.

If this sounds like a lot to do, don't let that put you off: It's part of the fun of using a sundial.