purpose of moving the hands over the dial, if the probabilities of unvarying accuracy are not lessened, the cost must be much increased. Works which have to be placed at some distance from the dials must be more powerful than if they could be put in their proper place, and a little forethought in the architect will save much money both in the original price of the machinery of a clock and in its subsequent repair. Then again, there is always the question for and against the illumination of dials to be considered, and of course with this is unavoidably mixed up not only the arrangements as regards space for the proper working of the time-keeping, striking, and lighting machinery, but the vexed question of ventilation above referred to,--some horologers asserting that chambers as nearly air tight as may be should be devised, and others that there ought to be a draught through the clock-room. There are in fact so many opinions more or less excellent, according to the circumstances of each case, that there is no laying down any arbitrary and unvarying rule, much must be left to the discretion of the Turret Clock manufacturer,--upon whom as has been already stated it is necessary also to rely for the essentials of a good clock, viz., the soundness of the materials, the quality of the workmanship, and the scientific accuracy with which the instrument has been planned and put together. Now before considering the present advanced state of the art of Turret Clockmaking and the various improvements which have to be carefully studied and applied by the makers who would bear the highest reputations as manufacturers, it will be necessary to bear in mind what has been said of the step-by-step progress in horological science of which we have already endeavoured to give the chief particulars. From 1288 A.D., the date of the oldest historical clock--that mentioned as having been set up near Westminster Hall by means of funds derived from a fine levied by the Lord Chief Justice of the period--till now when Big Ben reigns in its stead, is a long interval, with many wonderful incidents, and some great historical names. Henry de Wyck's Paris invention, Galileo's discovery of the pendulum, Huygens's practical application of that discovery, Dr Hooke's 'anchor' escapement, and Graham's dead-beat escapement, Harrison's 'gridiron' pendulum, and the latest applications of electricity and eccentricity, have each and all their peculiar attraction for horological students, but we need not recur to these branches of this highly interesting subject elsewhere treated of. We will proceed to mention a few memoranda about several old public clocks whose ingenious mechanism gained for them a well-deserved fame,--not, perhaps, so much for accuracy in time-keeping as for the grotesque devices with which old clockmakers amused their contemporaries? To them time, as such, was perhaps of not so much consequence as it is to us in these days of telegraph and steam communication.