208 PROGRESS OF METEOROLOGY IN 1889. 



The sixth volume of the Eeports of the International Bureau of 

 Weights and Measures contains three papers of importance to instru- 

 mental meteorology in continuation of the valuable memoirs published 

 in the preceding volumes, which include researches on the tensions of 

 aqueous vapor, on the fixed points of thermometers, on the true 

 weight of a litre of air, on the dilatation of mercury, on methods of 

 verifying subdivided linear measures, on calibrating thermometers, 

 and other thermometric studies. Of the papers in the new volume that 

 are of meteorological interest, one (tome vi, pp. 620) is by Dr. IJene 

 Benoit, on the measurement of dilatations by the method of M. Fizeau ; 

 one, on the comparison of mercurial thermometers with the air or hydro- 

 gen thermometer, by Dr. P. Chappuis ; and a third paper, on practical 

 formula) for the transfornuitiou of thermometric co-efficients, by Dr. A. 

 E. Guillaume. 



JDaily synoptic ivcather charts for the North Atlantic Ocean, Parts 1 

 to 5, September, 1883, to I^^ovember, 1884, have been published con- 

 jointly by the Danish Meteorological Institute, and the Seewarte at 

 Hamburg. Each volume contains a carefully prepared summary of the 

 principal meteorological features. A novel point in the work is the 

 introduction by Dr. Koppen of a new system of discussing the paths 

 of storms in which their rate and direction of motion are shown to be 

 dependent on snrrounding conditions; so that the movement of cy- 

 clones is almost entirely dependent on their relation to existing anti- 

 cyclones. Dr. Koppen finds one type of conditions to consist of an 

 almost stationary anti-cyclone with a cyclone traveling along its bor- 

 ders. He then proceeds to represent all periods of this type on one 

 chart, the number of such periods in the year ending with August, 

 1884, being fifty-seven, each ranging from three to eleven days each. 



The movements of the cyclones during the type are represented by 

 lines joining the ascertained positions each day, and by a simple ar- 

 rangement the lowest pressure and the wind force are represented 

 dailj'. The anti cyclones are considered as stationary and the isobar 

 of 30.12 inches has been adopted and plotted as the inclosing periphery 

 of such areas; its position is the mean position of that isobar during 

 the period ; the maximum barometric readings are shown near the 

 center, and the direction in which the highest .i)ressures moved. By 

 this method the representation of storm tracks has been greatly sim- 

 plified. In some special cases one chart has been devoted to a single 

 period showing conditions of marked interest. In the study of trop- 

 ical cyclones the positions of neighboring anti-cyclonic areas is shown 

 to govern the various paths pursued. 



The publication of synoptic weather maps twice a day was begun by 

 the Central Physical Observatory May 12, 1881). The map covers the 

 whole of Europe, and a summary of the weather is given in Russian 

 and French. 



Lady Franklin Bay Expedition. — The official report of the Lady Frank- 



