220 



NATURE 



[April 21, 19 10 



THE FREE ATMOSPHERE.' 



I'^HE publication referred to below adds yet another 

 to the series of memoirs issued by the Meteor- 

 ological Office in the past few years. It furnishes an 

 example, of comparatively rare occurrence in original 

 scientific investigation, of the successful cooperation 

 of private and official enterprise. 



The introduction by Dr. Shaw contains a short his- 

 torical account of the progress made in the investiga- 

 tion of the upper air and a summary of the more 

 important results obtained. It includes a welcome 

 bibliography of the chief English publications on the 

 subject. 



The work in this country was begun so long ago as 

 1749 by Wilson and Melville, of Glasgow, and the 

 balloon ascents of Jeffries, and, later, of Welsh and 

 Glaisher, maintained our position in the forefront of 

 upper-air research. After a period of comparative in- 

 action, the investigation was renewed at the instiga- 

 tion of Mr. Dines at the beginning of the present 



6 inches midway between them. This kite is used if 

 the wind aloft is likely to exceed 40 miles per hour. 

 Steel piano wire, 1/32 inch in diameter, having a 

 breaking strain of 250 lb., is used with all the kites. 



If, when a kite is flying, it appears probable that 

 putting on more kites, or letting out more wire, will 

 increase the strain to more than 100 lb., the attempt 

 is not made owing to the risk of breaking the wire, 

 especially as records from greater heights can be 

 obtained with registering balloons. It ought, how- 

 ever, to be borne in mind that the results for tempera- 

 ture and humidity obtained by balloons are less trust- 

 worthy than those obtained by kites, and this is of 

 especial importance in connection with the daily varia- 

 tions. A kite can be kept for some time at a nearly 

 constant level, and the kite and instruments remain 

 exceptionally well ventilated without artificial means. 



Dines's use of embroidery cambric at gd. per yard, 

 and black dress lining at 5^. per yard, for his sails 

 recalls Stokes's marked preference of candles for his 

 optical experiments. The art of using the simplest 



century. Dines began his work on the west coast 

 of Scotland in 1902-4, and continued it, first at 

 Oxshott, 15 miles south-west of London, and after- 

 wards at Pyrton Hill, 40 miles west by north of 

 London. 



The report deals with kites, pilot balloons, and 

 registering balloons, and contains a summary and 

 brief discussion of the results obtained. 



Three kinds of kites, all of the box pattern, are used 

 at Pyrton Hill. No. i is 9 feet high, and has sails 



3 feet wide and 18 feet long. It is used in light winds. 

 No. 2, for standard use, is very similar, but the sails 

 taper from 3 feet at the front and back sticks to 2 feet 



4 inches at the sides. No. 3 is only 7 feet high, and 

 the sail edges form arcs of circles, the width of the 

 sails being 2 feet 6 inches at the sticks and i foot 



1 M.*^. 202. "The Free Atmosphere in the Region of the British Isles." 

 Contributions to the Investigation of the Upper Air, compris.ng a Report by 

 W. H. nines, F.R. S., on Apparatus and Methods in use at Pyrton Hill, 

 ■with an intr. diiction and a note on the Perturbations of the Stratophere by 

 Dr. W. N. Shaw, F.R.S., Director of the Meteorological Office. Pp. iv + 56. 

 (Lor.don : H. M. Stationery Office, 1900.) Price 2^. 6d. 



NO. 21 12, VOL. 83] 



things to the best advantage runs some danger of 

 being lost in the laboratories of ready-made apparatus 

 and "arranged" experiments. It is refreshing to find 

 instances of it in an official publication. 



A good deal of trouble is taken to make clear, by 

 diagrams and description, the method of letting-out 

 and winding-in the kite wire. Mr. Dines having dis- 

 covered, by long practical experience, the places where 

 difficulties arise has taken the trouble to invent the 

 necessary safeguards and to give to others the benefit 

 of his labours. 



The meteorograph used with kites is shown in Fig. 

 I, A, B. ; Fig. I, B, shows the exposed under-surface 

 of the apparatus. The separate parts are (i) the lever 

 and thread of the anemometer ; (2) the thermometer, a 

 spiral metal tube containing spirit ; (3) the clock ; (4) 

 the cover of the aneroid barometer; (5) a metal cover 

 protecting the hair of the hygrometer. In Fig. i. A, 

 the recording pens are (i) humidity, (2) atmospheric 

 pressure, (3) temperature, (4) wind velocity. The sur- 

 face shown in Fig. i, A, is covered by waterproof clolh 



