SCIENTIFIC SLN^]MARY. 
383 
that were found had been divided by a very fine saw, as was proved by the 
absence of marks of graining on the surface of the sections. 3rd. On some of 
the bones there were furrows, evidently made by sharpening fish-hooks or 
some pointed implement on them. 4th. In various places nests of jperoxido 
of iron were observed, as if an iron instrument had once been there, but had 
been corroded away in course of time. Mr. Kinahan draws particular 
attention to the circumstance that “ few metals corrode as fast as iron, and 
that, while stone and bronze would last for ages, iron would disappear, ovdng 
to corrosion, in a comparatively short space of time.” 
Eozoon in Britain. — The fossil Rhizopod, which has lately attracted so 
much attention in these countries and abroad, is, it appears, not confined to 
the Canadian rocks. Mr. W. A. Sandford has discovered Eozoon in the 
green marble rocks of Connemara, in Ireland. His assertion that it is to be 
found in these deposits at first excited very grave doubts as to the accuracy 
of his observations. Since his first announcement of the discovery, his 
specimens have been examined by the distinguished co-editor of the Geolo- 
gical Magazine (Mr. H. Woodward), and this gentleman fully confirms 
Mr. Sandford’s opinion. In the specimens prepared from Connemara 
marble, “ the various-formed chambers — the shell of varying thickness — 
either very thin, and traversed by fine tubuli, the silicate filling which 
resembles white velvet-pile, or thick, and traversed by brush-like threads, are 
both present. Although the specimens were not so carefully prepared as 
those mounted for Dr. Carpenter, still the structure was so plainly perceptible 
as to render the diagnosis incontrovertible. 
A neiv “ Coal ” Reptile. — Professor Owen has described a fossil from the 
coal-beds of GHmorganshire, and given it the name of Anthraherpeton 
crassosteum. The bones examined were those of a batrachian vertebrate 
resembling the saurians in some respects. He supposes it to have belonged 
to that “ low, probably primitive, air-breathing type which, with develop- 
mental conditions of the bones like those in some fishes, and very common 
in Devonian fishes, showed forms of the skeleton more resembling those in 
sauria.li reptiles than are attained by any of the more specialized batrachian 
air-breathers of the present daj^” The specific name refers to the density and 
thickness of the long bones which the Professor examined. — Vide The 
Geological Magazine, January. 
MECHANICAL SCIENCE. 
Small-wheeled. Locomotives. — Mr. Zerah Colburn has published a paper 
advocating the return to smaller driving-wheels in fast passenger engines, in 
accordance with American and Continental practice. With a given tram, 
resistance at a given speed, the smaller the driving-wheel the shorter must be 
the stroke and the greater the piston speed. The earlier locomotive engmeers 
imagined that a mean piston speed of 500 feet per minute should not be 
exceeded, and built their engines accordingly ; but the exigencies of more 
recent practice have compelled the adoption of a speed of 1,000 feet per 
minute, or more, without ill effect ; and even this speed may, in Mr. Colburn’s 
opinion, be exceeded with safety. By adopting a high piston speed and 
small driving-wheels, the following advantages are gained : — 1st. The centre 
