GENERAL CONSIDERATION
[23.]Optional Allowances for Variation.
The phrase "Adjusted to Isochronism and Positions" does not always indicate the same high quality or the expense assumed in obtaining close rating in different kinds of watches.
One particular model may be stamped "Adjusted to Five Positions" and this may indicate that the manufacturer of this model has tested all watches of this grade for twenty-four hours in each of five positions and that the extreme extent of variation from one position to any other, among any of these watches, did not exceed six seconds. Another model may be stamped in exactly the same way and it may indicate that all watches of that particular grade have been tested in exactly the same way and that the extreme extent of variation from one position to any other, did not exceed twenty-five seconds.
The statement regarding the number of positions to which the watch has been adjusted is just as legitimate in the latter instance as it is in the former, for the watches are really tested in five positions and required to perform within specified allowances.
The important difference is in the established limits of requirement, one demanding an extreme of only six seconds variation and the other allowing twenty-five seconds. Both watches may have the same number of jewels and there is no way to discern the actual variation except through a test in positions.
Technically it would be just as legitimate to stamp and advertise watches as above and have an allowance of fifty or more seconds, providing that they were actually tested and not allowed to pass with a variation greater than this limit.
Close limits of allowance require adjusters of greater skill and material of a finer degree of accuracy, however, than do greater allowances, but the dealer and consumer are generally not informed in regard to this particular point. Some watchmakers also do not understand this feature clearly and the limits of variation to which watches have been adjusted are seldom considered.
Should the difference in allowances and identical advertising be interpreted as an injustice to the manufacturer who maintains close limits for his various grades of watches, it must be remembered that they speak for themselves after passing over the counter and into the hands of satisfied customers. His reputation after a period of years will be more firmly established than will that of his less particular competitor in the high grade field. A similar situation prevails in the repair shop, and the fact that many of the leading dealers and railroad watch inspectors require at least a three position adjustment in the repairing of high grade watches, is convincing evidence that position rating demonstrates its importance in actual service when applied to repair work, as surely as it does when applied to new watches.
In placing limits of allowance for variation in various grades it is not intended that all watches of a particular grade will have the extreme variation. It is possible that an individual watch in the twenty-five seconds allowance class may have an even better rate than another watch that is in the six seconds class. It is also possible for a watch in either class to have a perfect rate, although these would be rather exceptional instances.