Notice, too, that the blades of the propeller are each bolted to the shaft, and that the latter terminates in a conical shape now so common on screw-ships. This is called the “boss,” and was invented by Robert Griffiths in 1849. It was introduced in order to reduce the pressure of the water towards the centre. This method was first tried on a steamer in the following year at Bristol and afterwards on H.M.S. _Fairy_. By reason of its shape, it naturally causes less resistance through the water. Whilst these lines are being written, there are building at Harland and Wolff’s yard still another couple of ships for the White Star flag, which, if not in speed, will be the most wonderful, and certainly the largest ships in the world. After the _Baltics_ and _Mauretanias_ one feels inclined to ask in amazement: “What next, indeed?” They will measure 850 feet long, 90 feet broad, and be fitted with such luxuries as roller-skating rinks and other novelties. They will each possess a gross register of 45,000 tons. (By way of comparison we might remind the reader that the _Mauretania_ has a gross register of 33,000 tons.) Named respectively the _Olympic_ and _Titanic_, they will be propelled by three screws, and have a speed of 21 knots, so that besides being leviathans, they will also be greyhounds, and are destined for the Southampton-New York route. The first of these, the _Olympic_, will take the water in October, 1910, and some idea of her appearance may be gathered from the illustration which forms our frontispiece. Like the _Laurentic_, these ships will be fitted with a combination of the turbine and reciprocating engines, and will thus be the first ships running on the New York route to have this system. Their builders estimate that the displacement of each of these mighty creatures will be about 60,000 tons, which is about half as much again as that of the _Baltic_. Each ship will cost at least a million and a half of money, and it will be necessary for each of those harbours which they are to visit to be dredged to a depth of 35 feet. It is a complaint put forward by both ship-builders and owners of modern leviathans that the governing bodies of ports have not shown the same spirit of enterprise which the former have exhibited. To handicap the progress of shipping by hesitating to give the harbours a required depth, they say, is neither fair nor conducive to the advance of the prosperity of the ports in question, and on the face of it, it would seem to be but reasonable that if the honour of receiving a mammoth liner means anything at all, it should be appreciated by responding in a practical manner. In New York Harbour this fact is already recognised, for dredging is being undertaken so as to provide a depth of 40 feet.