1 74 The Rev. T. R. Robinson's Description of an improved Anemometer. 



velocity was of nearly the same amount, the sudden diminution of roar led me 

 to suppose the gale was abating ; but, on going to the instraraent, I found the 

 velocity had increased to 52, while the range of direction was only half its pre- 

 vious extent. 



The contrivances which I have applied as checks on the direction-fluctua- 

 tions seem to work well. In the first place, such as are completed in a second 

 or two are chiefly expended in bending the spring L, being past before its ten- 

 sion can overcome the inertia of the paper-holder and its machinery. Secondly, 

 the wheel G drives a regulator attached to the arbor of the pinion I, but not 

 shown in the drawing. This consists of foiu- vanes, 

 shown in plan. Fig. 3, made of light deal frames covered 

 with paper. Each is 37 inches high and 15 broad. As 

 the whole is very hght and turns on an agate, it yields 

 to the slightest impulse of the vane, if time he given, but 

 presents a very great resistance to rapid motion. Its 

 speed is ^ times that of the vane,* and this, combined ^'g. 3. 



with the action of the spring, will often reduce the oscillations to one-third of 

 their absolute magnitude. As at first appUed, the regulator was much smaller 

 and immersed in water ; but I was obliged to abandon that plan, in consequence 

 of its action being interrupted during frost. 



Lastly, Plate V., fig. 6, shows the method of connecting these two registers 

 with that of time. N is a cast iron plate which bears the whole machinery. 40 

 inches by 14. P and P' are the paper-holders ; each has three spring-clips at 

 its circumference, to hold the paper, which is further secured by the screw H 

 passing through a hole punched in its centre ; this screw serves also to centre it, 

 being of the same size as one of its circles. One of these clips bears a fiducial 

 line, with which the zero of graduation is made to coincide when a new paper 

 is applied. M is a common clock movement, the weight and pendulum of 

 which pass through openings in N. Its barrel carries a second wheel, which 

 moves, by a rack, the bar pp' through six inches in twelve hours. This 



* I have since added an intermediate wheel and pinion, which makes the speed ?f x |^ = 28'8, 

 which is a considerable improvement. 24 might be immediately obtained, and would be, perhaps, 

 the best. 



