Page:Popular Science Monthly Volume 15.djvu/709

 Of course, every word that I here say as to the usefulness of warnings is just as true with reference to warnings issued by our own office in London as to those of the "New York Herald," but these latter are often very general in their scope. They speak occasionally of a storm reaching the British Isles and France, and affecting Norway. This haul of the net embraces 25° of latitude, from 4°5 to 70°, and it is an unheard-of thing that a gale should prevail simultaneously over such an immense tract of coast, so that on each occasion the seamen in many harbors can not derive immediate benefit from the publication of so vague an announcement.

It is one thing for a scientific man to say that he can recognize the presence of the predicted cyclone on our coast—Professor Loomis admits that the chances are even that he should do so—but it is a totally different matter to prove that a gale which begins two days before or two days after the time of a predicted storm, is really the very disturbance which left the American coasts.

The experience of those who have studied cyclone tracks in northern Europe shows that in winter, on an average, a cyclonic disturbance visits some parts of those regions every fourth clay, so that, if a warning were announced once a week regularly, there would be nearly a certainty of some sort of a fulfillment.

The results of a most careful comparison of these warnings with the weather experienced by us during the years 1877-'78 are given by the following percentage figures:

In order to obtain so favorable a result as forty-five per cent, of general success, great allowances have been made. Thus it has been considered an absolute success if a gale was felt on any part of the coast, whereas the prediction was for all parts; and when three separate storms were predicted in one telegram, none of which arrived, only one failure has been counted.

It is, therefore, pretty clear that these warnings have not, as yet, proved themselves to be of much practical utility to our coasting trade and our fishermen. The question is a most interesting one, and although a satisfactory solution of it has not been attained, we need not despair; but we should attack it from the scientific side, and discuss the results in a calm, dispassionate spirit, and through some other medium than that of letters to newspapers.

Let us now leave these American warnings, and see what we know about the movement of storms over western Europe, which is the problem which most immediately concerns us here. The illustration has often been used that meteorologists, in issuing storm-warnings, and