The possible variability of the Am stars lead me to reexamine and extend my
results for the hotter "non-magnetic" HgMn stars. Observations of 53 Tau,
HR 4072, and HR 6096 (later shown to be a HgMn star by Lopez-Garcia &
Adelman 1994) made during the first two years of the FCAPT (Adelman 1993)
and of 
And (Adelman et al. 1994) made with the same telescope
showed that these stars were constant. A reexamination of the data in the
literature agreed with this conclusion.
After a reexamination of the data made during years 1 and 2, there are respectively 6 and 17 good observations of 53 Tauri (= HR 1339 = HD 27295) in Adelman (1993). During year 3, 18 observations were made (Table 5). There is no evidence for variability within a year. The averages for years 2 and 3 differ by about one-half the standard deviations of the means. Those values for year 1 usually are slightly more discrepant which suggests a slight difference in the atmospheric extinction.
Adelman (1993) reported on 24 uvby observations of HR 4072 (= HD 89822) made during year 2. Table 5 presents 6, 36, 51, and 50 sets of values from years 3, 4, 5, and 6, respectively. Except for the v-ch and ch-c values of v for year 6, the yearly means are quite close to one another and within each year there is no evidence of variability.
Adelman (1993) gives 24 uv and 12 by observations of HR 6096 (= HD 147550) made in year 1 and 26 uvby values for year 2. Table 6 contains 6, 16, 26, and 29 uvby observations made during years 3, 4, 5, and 6, respectively. As for HR 4072, the v-c, v-ch, and ch-c values for each year and magnitude are close to one another except for the v-ch and ch-c v values for year 6. For both stars these are offset by about 0.045 magnitudes suggesting that something happened to produce this offset, perhaps a change in the extinction or for both stars a change in the check star as the v-c averages are consistent between years.