METEOROLOGY AND ALLIED SUBJECTS. 



255 



The observers at Russian stations rarely estimate the wind velocity, 

 but observe the angles of deviation of Wild's tablet anemometer, which 

 are converted into the Beaufort scale before being telegraphed. They 

 may therefore be converted into true velocities by means of Dolirandt's 

 investigation of the normal tablet anemometer at St. Petersburg, and 

 the scale of velocities adopted by E. H. Scott, as shown in the following 

 table: 



{Z. 0. G. M., XIV, p. 304.) 



The construction of lightning-rods, and the statistics of injurj' by 

 lightning, have been discussed by Eichard Anderson, who states that in 

 England one-half or two-thirds of public buildings are without light- 

 ning rods, and that of private buildings, not five in a hundred are pro- 

 vided with them. The injury annually done by lightning is very great, 

 as also the number of lives lost through its means. We are within 

 bounds when we estimate that in England and Wales there are on the 

 average as many deaths from lightning as there are in Prussia, for 

 which we have accurate data, and the sum total for all three countries 

 amounts to one hundred and fifty persons. The reason of this loss of 

 life lies not only in the omission to erect lightning-rods, but from the 

 poor character of those which are often put up, and also in the neglect to 

 carry out a system of inspection in order to insure that the rod continues 

 to be still in good working order. Thus it seems incredible, but it is a 

 fact, that the royal castle at Windsor is almost entirely without light- 

 ning-rods, and in some portions is provided with those too small to be of 

 any use. Many come to the erroneous conclusion that lightning-rods 

 are of no use, but this is due to their improper construction and insuffi- 

 ciency of numbers. As regards their inspection, it would seem remark- 

 able that every part of a large building is annually repaired, painted, 

 &c., while a lightning-rod, when once established, is never looked after, 

 and yet its efiiciency can be injured at any moment lo such an extent 

 that it may become a source of danger rather than a safeguard to the 

 building. {Z. 0. G. M., XIV, p. Go, 1870.) 



Dr. Paul Schreiber, whose improvements in the self-recording balance 

 barometer are above noticed, states that he has been able in the instru- 

 ment established at the Deutsche Seewarte to reduce the uncertainty 

 of the record (due principally to frictional resistances) to 0,2°"° j but, 



