218 REPORT—1874. 
revolving lights. He has also, in both these cases, applied with the most striking 
success the principle of occultation. Dr. Tyndall, in his Reports to the Board of 
Trade, has dwelt frequently and emphatically on the ease with which gas lends 
itself to the individualization of lights. By its application he affirms that, hy simple 
arrangements, it would be possible to make every lighthouse declare its own name. 
Within about the last two or three years, the subject has been taken up energeti- 
cally by Sir William Thomson. He has become strongly impressed with the 
enormous importance of the object in question. He has perseveringly laboured in - 
making trials in various ways, both by the method of partially extinguishing gas- 
flames and by the method of revolving screens; and I have pleasure in stating that, 
as a result of his efforts, a self-sigralling apparatus is now constructed for the Bel- 
fast Harbour Commissioners, who are preparing to bring it into immediate use at 
the screw-pile lighthouse, at the entrance of the harbour of Belfast. I shall not 
now enter on any description of this arrangement, as I understand that the appa- 
ratus, which has already been temporarily erected for trial in the lighthouse, and 
has shown good results, is to be exhibited and explained to this section by Mr. 
Bottomley, who, as a member of the Board of Harbour Commissioners, has taken 
an active part in the promotion of the undertaking. 
I wish next to make mention of the very remarkable works at present in progress 
in the Harbour of Dublin, under the designs and under the charge of Mr. Bindon 
Stoney. In order to form quay walls with their foundations necessarily deep under 
water, he constructs on land gigantic blocks of artificial stone, or, as we may say, 
of concrete masonry, each of which is about 350 tons in weight, and which are 
accurately formed to a required shape. After the solidification of the concrete, he 
carries them away, and deposits them on an accurately levelled bottom of the sea, so 
that they fit closely together, and form so much of the quay wall in height as to 
reach aboye the low-tide level, and so as to allow of the completion of the wall 
above by building in the usual manner by tidal work, and to allow of the whole 
structure being carried out without the use of ecoffer-dams. These operations are 
on a scale of magnitude far surpassing any thing done before in the construction 
and moving of artificial stone blocks. They are carried out with machinery and 
other appliances for the removal and the placing of the blocks, and for other 
id papa of the undertaking, which are remarkable for boldness of conception 
and ingenuity of contrivance. The new methods of construction devised and 
applied in these works by Mr. Stoney are recognized as being admirably suited for 
the local cireumstances of the site of the works in the Harbour of Dublin, and their 
various arrangements form a very important extension of the methods of construc- 
tion available to engineers for river- and harbour-works, 
While progress has been made with gigantic strides in many directions in 
engineering and in mechanics generally, while railways, steamboats, and electric 
telegraphs have extended their wonders to the most distant parts of the world, 
and while trade, with these aids, is bringing to our shores the produce even of the 
most distant places to add to our comforts and our luxuries, yet, when we come 
to look to our homes, to the places where most of our population have to spend 
nearly the whole of their lives, I think we must find with regret that, in matters 
pertaining to the salubrity and general amenities of our towns and houses as 
places for residence, due progress in improvement has not been made, Our house- 
drainage arrangements are habitually disgracefully bad; and this I proclaim 
emphatically, alike in reference to the houses of the rich and the poor. e haye 
got, since the early part of the present century, the benefits of the light of gas inour 
apartments; but we allow the pernicious products of combustion to gather in 
large quantities in the air we have to breathe; and in winter eyenings we liye 
with our heads in heated and vitiated air, while our feet are yentilated with a 
eurrent of fresh, cold air, gliding along the floor towards the fireplace to be drawn 
uselessly up the chimney. A very few people have commenced to provide chimneys 
or flues to carry away the fumes of their more important gas-lights, in like manner 
as we have chimneys for our ordinary fires. In mentioning this, however, as a 
suggestion of the course in which improvement ought to advance, I feel bound to 
offer a few words of caution against the introduction of flue-pipes for the gas- 
flames rashly, in such ways as to bring danger of their setting fire to the house. 
