The familiar dotted lines termed isobars, which are such a feature in weather maps of this sort, are lines at all places along which the barometer stands at the same height. Except where their regularity is broken by the existence of subsidiary disturbances, these lines extend in gradually widening circles around a centre of depression, the barometer always standing highest along the outside curve, and gradually and regularly falling towards the centre; so that if we could view our atmosphere from above one of those centres of depression, we would see a deep hollow, with sides sloping downwards to the centre, towards which the revolving air was being gradually indrawn, like water in an eddy. At intervals, we receive warning across the Atlantic, from the _New York Herald_ weather bureau, respecting storms which are crossing the Atlantic towards our coasts, and which are often described as ‘likely to develop dangerous energy’ on their way. Although many of those warnings are subsequently justified, or partially justified, it must not be supposed that these are storms which have left the American continent on their way to us, and that it has been possible to calculate their course across the Atlantic and predict the time of arrival upon our coasts. Mr Clement Ley, Inspector to the Meteorological Council, tells us that it is not yet satisfactorily shown that storms cross the Atlantic from America, and he presumes that arrangements must be effected by which the logs of passing steamers may be consulted in America as to the character of the weather experienced in crossing from this country; and from the information received in this manner, it is possible to arrive at conclusions respecting the direction and character of storms travelling towards this side of the Atlantic, and to anticipate their arrival by telegraph, the warning being flashed beneath the ocean in time to reach us long before the storm itself.