The Director of the Observatory at Sicawei regrets to observe that those who are interested in the modifications that have been recently introduced into the signal service have not all paid sufficient attention to them, On one day the mid-day gun was, fired in Shanghai at 11,55 a.m, instead of noon, The modifications referred to have not been introduced without reason. It is unnecessary to point out to sailors the advantage of having the rate and state of their chronometers determined as perfecti sible. Roughly, no doubt, it is enough to know the state of one's chronometer tos second, but its rate must be more exactly determined, as, if not, every dey will add an error of another second to its presumed state. Every-one knows that when it is necessary to determine a very small interval of time, such as the fraction of a second, two observations are much more certain than only one, and that by taking the mean of two successive observations to get the true value, it is much easier to avoid a serious error. It is not, therefore, to enable the observer to choose which of the two signal she will take thatthe change inthe service has been made, but to enable him by means of the two successive signals, at 11.55 a.m, and at noon, to get the time with greater accuracy.
The readings taken at the observatory at Sicawei every day at 10 a.m. are posted up at the Semaphore at 11.30. These ought to interest the general public as well as the students of meteorology. The bul-latin contains the variations of the different meteorological elements for 24 hours, and the comparison of the means of the preceding day with the normal means for the previous thirteen years. In addition there are important remarks on the state of the coast from the meteorological point of view. These remarks are not merely a resume of the despatches received before 10a.m., but the fruit of a careful study of these despatches, and they require an attentive comparison of the despatches of the day with those of the preceding days. Sometimes it is added what weather may be expected. Itis not tobe imagined that the director of the observatory pretends to the gilt of prophecy, or believes that his prognostications are infallible. Rain sometimes comes when fine weather is expected. Certain facts may be usefully noted: the bulletin of the 22nd March announced that there would be bad weather in the Corean Channel. The despatches from Nagasaki fully justified this. The bulletin of the 24th announced that it was probable that a squall would come from the interior. On the next night a violent squall from the northwest came to confirm the prognostication. Meanwhile it must not be forgotten that the observatory is unfavourably situated for the prediction of the weather, in that it has mostly to rely on its own unaided observations. It is true that it receives despatches from some of the ports on the 1 enacts of China and Japan; but these despatches, while very useful for communicating and giving a general view of the more marked movements of the atmosphere, are, except in the more important eases of typhoons, more or less useless for weather prediction. Japan can no more warn us of the squalls that are going to drop on us suddenly, than Europe can warn America of the blizzards that are about to visit it. The warnings must come from the other side. As for the communication with the South, we can tell if a depression which has reached Shanghai will reach the South at the same time or a little later, but never, or very rarely, if a little earlier, saving always in the case of typhoons, It is from the interior, from the West, the North, and the farthest telegraphic stations in the North-West, that advices are wanted. When may we hope that this want will be gratified
Text read from the printed page and cleaned; old type leaves the occasional error.