The glasses with straight-sided bowls may, on the whole, be attributed to an early period, and together with the contemporary bell-shaped glasses they constitute an essentially English class. Those again with the so-called ogee bowls are especially associated with the Bristol glass-houses. Glasses with bowls of this outline form nearly one-third of the extensive collection of Mr. Singer, which was formed for the most part, as I have already mentioned, in the neighbourhood of that town. I now turn to the engraved designs that are found upon the bowls of most of these eighteenth-century glasses. There is not much to be said for the inventive powers or for the technical skill shown by the engraver. Indeed, considering the general low level of the engraved work, there is some temptation to find a Dutch or Flemish origin for any specimen of engraving that shows superior technical or artistic qualities; and there is little doubt that in the case of the earlier pieces at least, such an attribution would be justified.[257] The design that we find most frequently on our eighteenth-century glasses is a rose branch with, on the opposite side, a butterfly. This motive is found on the bell-shaped bowls of early glasses with air-twisted stems. With certain modifications it continued long in use. The rose, with the change of fashion after the middle of the century, became more naturalistic, and the butterfly often takes the form of a moth. Other designs have reference to the beverage destined to be drunk from the glass: for wine-glasses, bunches of grapes and vine-leaves (often accompanied by a humming-bird); ears of barley for beer-glasses; and in the few rare cases where an apple-tree forms part of the design, we may associate the glass with cider. The popular cries—‘No Excise,’ or ‘Wilkes and Liberty’ and ‘No. 45’—which are sometimes found on glasses towards the middle of the century,[258] remind us of the new fashion that came in about that time of finding in the decoration of pottery or other ware an opportunity for political propaganda, and for the glorification of the hero of the day. There was not much to be done in this way on the restricted space at command on the bowls of our glasses; towards the end of the century, however, naval emblems are frequently to be found, and the Nelson glasses form a group by themselves.