Performance of Some Timekeepers. 187 



profess to be adjusted, yet it is within those limits ; I consider 

 myself, however, a careful wearer. 



To dispense with the tedious and expensive process of 

 adjustment for position, an arrangement has been introduced 

 by the Swiss, called a " tourbillon." In this system the 

 escapement and balance are mounted on a frame which 

 makes a complete turn in the watch every two or three 

 minutes. Some of these tourbillons have given very good 

 results. The method does not seem, however, to be growing 

 into favour, owing, perhaps, to its being less stable than the 

 ordinary construction. A somewhat similar plan is found in 

 the Waterbury watches, mentioned before in connection with 

 the duplex escapement, where the whole movement turns 

 in the case once in an hour. 



As a final remark to the purchasers and owners of watches, 

 I would say to the former, buy your watches from trust- 

 worthy men — those whose words are as good as their bonds. 

 Do not be led away by surface appearances, the number of 

 jewels, «fec. Saunier remarks that — " In a vast number of 

 modern watches, and, unfortunately, even in many of those 

 which pretend to be of superior quality, the jewels are 

 rather a blind than in any sense beneficial. Badly worked 

 and of insufficient hardness, these are less serviceable than 

 good, carefully hammered brass." Watch jewels are by no 

 means so valuable as is usually supposed. The cost of a 

 jewelled hole of good average quality, ready for fixing in the 

 plate, is, I am informed, in Geneva, only one shilling. The 

 Swiss occasionally put a glass back to their watches in place 

 of the usual metal dome, so that the works may be seen 

 without opening and exposing them to dust, &c. It is a 

 very bad style, however, for should the glass get fractured 

 the particles fall at once into the movement, and do great 

 damage. I am told that one of the fine Swiss watches that 

 came out highest at our Observatory testing has been lately 

 irretrievably ruined owing to this. Compensation balances 

 also, unless carefully made, are worse than plain ones, for, 

 independently of their never having been adjusted, the arms 

 oftentimes move unequally with change of temperature, and 

 thereby cause great errors of position. As a general remark, 

 it may be stated that good watches are seldom unsightly. 

 To the owners of good watches I would say, treat them with 

 the greatest care and gentleness, for they are most delicate 

 machines, and worthy of being treasured as specimens 

 of man's intelligence and manipulative skill. Never allow 



