I ordered 2 Patterson certified thermometers. I’m glad to say they both read exactly the same temperature. Very good value and arrived on time, as expected. I’d certainly use Speed Graphic again. Curiously, both thermometers are 0.3degC lower than my 47 year old Patterson certified mercury thermometer. Within tolerance. Interestingly enough the alcohol thermometers have slightly different size bulbs and correspondingly different length scales, as expected (in fonts of slightly different weight). I suspect these newer alcohol thermometers may be more accurate as they must have been calibrated at (at least) 2 temperatures, whereas the mercury thermometer has a little score mark at the 20degC point, which I suspect was done by hand and possibly with a scale of only one length.