BALLAST The displacement of a vessel is a quantity which enters very largely into any consideration of her stability, as was abundantly shown in a former chapter, and in no way does the knowledge of a yacht's displacement more largely assist the naval architect in his labours than in the matter of ballast. Most English yachts are built of pretty much the same scantling, and have similar internal fittings and spars; yet the weight, exclusive of ballast, of any two yachts of equal length and breadth may vary con siderably, as will be gleaned from the following table, abstracted from " Yacht Designing" : It is very evident that, the greater quantity of ballast a vessel has in proportion to her displacement, the lower ought to be her centre of gravity, and, as a sequence, the greater ought to be her stability. A yacht builder, therefore, even if he disregards the simple calculation of the displacement of a vessel he is commissioned to construct, will know that, so far as sail-carrying power is concerned, an advantage must accrue from making the fabric of the hull as light as possible, consistent with security, if the vessel be intended for racing.
But, as already pointed out, it must not be concluded that of two vessels of equal length, breadth, and draught of water, and equal scantling so far as sizes of timbers, beams, and planking go, the weight of the hull need be the same. The probability is that the vessel of the larger dis placement will carry the greater proportionate weight of ballast, as is very pointedly exemplified in the case of the Sappho and Guinevere. Now the Sappho is a much lighter-built boat than Guinevere ; yet, in proportion to displacement, it will be seen that she carries a smaller quantity of ballast. The reason of this is dependent upon the different forms taken by the vertical sections in the two vessels. The Guinevere's midship section is of the peg-top form, and the greatest girth of the midship frame, from the load line to the keel, is 16ft. ; the Sappho has a section very fiat from the bilge to the garboard, and then very curved. The consequence is that the girth or length of the frame, from the load line to the keel, is nearly 20ft. ; and there will be a proportionate excess of length in nearly every frame ; and as a consequence, an excess of plank as well. For this reason, unless vessels of similar linear dimensions be
also of similar form, they need not have the .same ratio of ballast to displacement. It will be noticed in the table that as the tonnage size of the yachts decreases the ratio of ballast to displacement increases ; the cause of this is that depth in a small yacht is relatiVely greater than in a large one—or, in other words, the depth is not made to decrease in propor tion to the decrease in the other two dimensions of length and breadth.* A very great change has been wrought in the manner of ballasting yachts during the last quarter of a century, and we cannot help declaring that generally a better type of vessel for speed and weatherliness has been built since ballasting has received greater attention. Scrap iron, fire bars, and even stone, were the common form of ballast in the first days of the Squadron, with a few shot bags to trim to windward in the event of match sailing. We all know that, as the pastime of yachting developed, a taste for yacht racing was very rapidly disseminated, and ballast shifting came to be regarded as part of the science of the sport ; and thus success, in fair sailing breezes, frequently rewarded the man who had the greatest weight of shot bags, and the greatest number of men to shift them. There is no denying that the absence of restrictions upon the shifting of ballast was introducing us to a very bad type of vessel, and the thanks of the present generation are due to the men who some twenty years ago succeeded in placing a stringent prohibition upon the practice of trimming ballast to windward. In 1856, in all competitive sailing, it was made a point of honour with yacht owners that they would not permit ballast to be shifted during a race ; and at the present time a man who is convicted of a breach of the rule is—or rather would be, as no breaches of the rule are brought to light—regarded as a little worse than a thief, and would certainly be ostracised by every yacht club in the kingdom. There is nothing heinous in the mere act of shifting ballast; but when the non-doing of it is made an affair of honour, it follows that dishonour must attend a breach of the rule.