Prof. Willis L. Moore, the chief of the Weather Bureau, in a recent address, published in the Marine Review, says :

"Any intelligent person, by studying the few simple principles on which the daily weather-map is founded, can make an intelligent estimate of the general character of the weather for his region, one, two, and at times, three days in advance.

" You may ask : Why has not this been done by the laymen, whose crops, whose perishable produce in transit, whose vessels exposed to the fury of wave and tempest, and whose health and pleasure are so dependent upon the weather and upon the sequence in which weather changes occur? In answer it may be said that many members of commercial associations, knowing the fluctuations in value of soil products that often result when rain falls on a parched district, when frost smites the corn in the milk, when hot south winds wither the crops in the great central valleys, or when clouds and moisture affect the condition of cotton, make a fairly accurate forecast of the weather from the large daily weather-maps displayed on blackboards before all the important commercial exchanges of the country, and in a pecuniary way largely profit therefrom. . . .

" By preserving the weather-charts each day and noting the movements of the highs and the lows, any intelligent person can make a fairly accurate forecast for himself, always remembering that the 'lows,' as they drift toward him from the west, will bring warmer weather and sometimes rain or snow; and that as they pass his place of observation, the ' highs' following in the tracks of the 'lows' will bring cooler and probably fair weather.

" He can closely forecast the temperature for his region by remembering that the weather will be cool so long as the center of the predominating high, i. e., the high enclosing the greatest area within the 30-inch isobar, is north of his latitude - either .northeast or northwest; and that it will be warm so long as the high is south of his latitude. . . .

" To get a rough idea of the difference between storms, we might classify them according to the diameter of the gyrating masses of air under their influence, as follows :

" Cyclones, 1,000 to 2,000 miles; hurricanes, 100 to 500 miles, and tornadoes, 100 to 1,000 feet. We might imagine their vortical action and their destructive force to increase in some ratio as their diameters of rotation decrease.

"The tornado is always an incident and a sporadic outbreak of the cyclone, and usually occurs in the southeast quadrant of a cyclonic storm.

"The thunderstorm, instead of rotating about a vertical axis, like the cyclone and tornado, has a horizontal roll, caused by cold and heavy air from above breaking through into a lighter and superheated stratum next to the earth. This rolling motion throws forward the cool air in the direction in which the cloud is moving. In general, thunder-storms move from the west toward some eastern point, the same as tornadoes, which mostly move from the southwest toward the northeast. If any part of the horizontally rolling air in the thunder-Strom drops down toward the earth and adjusts its rotation about a vertical axis it at once becomes a tornado, and its destructive force is increased a hundredfold.

" Large owners of marine property estimate that one severe storm traversing our Atlantic coast in the absence of danger warnings would leave not less than $3,000,000 worth of wreckage. On two occasions a census was taken immediately after the passage of severe hurricanes, to determine the value of property held in port by the danger warnings sent out in advance of the storms. In one case the figure was placed at $34,000,000, in the other at $38,000,000. Of course this does not represent the value of property saved. It simply shows the value of property placed in positions of safety as a result of the danger-signals displayed and the warning messages sent to vessel masters."

Consul Haynes of Rouen, under date of Aug. 26, 1901, says that the metric system is to-day compulsory in twenty countries, representing in all more than 300,000,000 inhabitants, - Germany, Austria-Hungary, Belgium, Spain, France, Greece, Italy, Netherlands, Portugal, Roumania, Servia, Norway, Sweden, Switzerland, Argentine Republic, Brazil, Chile, Mexico, Peru and Venezuela,- and advises American exporters in dealing with any of these countries to adopt the system.

In the June number will appear the first chapter of a complete description of how to make a wireless telegraphy apparatus. All the different parts will be fully described, so that any one desiring to make an outfit will have no difficulty in doing it. The item of cost has been carefully considered, and the expense will be the least at which workable instruments can be made. The same writer will also contribute articles on the making and operating of X-ray apparatus, and other instruments of interest to those engaged in electrical experimental work.

Numerous inquiries from our readers regarding directions for making an automobile at low cost lead us to request contributions on this subject. Any reader who has constructed a serviceable automobile at a cost of not over $100, and can give a clear and comprehensive description of how it was done, together with the necessary sketches, is requested to communicate with the editor in reference to contributing such a description for publication in this magazine. Such descriptions are desired for vehicles using steam and gasoline motor power, but must not be too complicated in design. If suitable arrangements can be made, such descriptive articles will be published with the expectation that many of our readers will utilize the information in constructing a carriage.

Our readers are invited to contribute to the correspondence column their experiences in making things described in this magazine. Many valuable suggestions would be obtained in this way which would be helpful to all.

The tables intended as a part of this month's chapter of Mechanical Drawing are omitted, but will appear in the next number.

It is reported from Vienna that a resident of that place, named August Matitsch, has devised a lace-making machine, which is said to produce lace which is indistinguishable from the hand-made article.