110 REPORT—1849; ~~ 
means of general education, the seeds of religion, virtue, truth, order, industry, and 
cleanliness ; but which seeds, to fructify advantageously, need, it is to be feared, a 
soil far less rank than can be found in these wretched abodes.” Such an evil con- 
dition of things could have but evil results, and the Registrar-General gives the fol- 
lowing mortality from cholera in Church Lane :— 
Metropolitan Buildings. 
Week ending 11 August, deaths from cholera...... 8 None 
” 18 2 »” eeece Oo None 
” 25 2 ae ee ae Peenare 6 None 
b 1Sept. ,, pe Aaeatatings VET 2 None 
» 8 ” a ak. ie Bate 3 None 
29 None 
Thus while the miserable abodes in Church Lane teemed with death, and the con- 
sequent panic put to flight and dispersed the mass of the wretched inhabitants, there 
was not a single case of cholera amongst a larger population in the buildings belong- 
ing to the Metropolitan Society. 

MECHANICAL SCIENCE. 
On a Centrifugal Pump. By J. G. Apron. 
Tur model of a centrifugal pump exhibited was capable of discharging 10 gallons 
of water per minute, and was only 1 inch diameter. One the same shape and 12 
inches diameter, will discharge at the same speed of the outside circumference, or 
one-twelfth the number of revolutions, 1440 gallons per minute. The author gives 
various other calculations, and observes, that from the results of various experiments 
he found the loss of power would not be more than 25 per cent. He also gives 
calculations of the height to which the pump will raise water without discharging 
any; as, for example, 1272 revolutions of the 1-foot pump will raise water 64 feet. 
_He has actually so raised water 67 feet 8 in, by 1322 revolutions, _The l-inch 
pump will discharge its contents above 30,000 times in a minute. 
On the Copying Telegraph, and other recent Improvements in Telegraphic 
Communication. By Mr. BAKEWELL. 
In the copying telegraph the corresponding instruments are made as exactly alike 
as possible, so as to impart equal and steady movements to a cylinder on each in- 
strument. Motion is given to the cylinders by weights, accelerated velocity being 
prevented by rapidly-revolving fans. Parallel to the cylinders are screws, which 
turn with the cylinders and carry traversing nuts. To these nuts ivory arms are ta- 
tached, at the end of each of which there is a binding screw to hold a metal point 
that presses on the cylinder, and is carried by the revolution of the screw from one 
end to the other. Upon the cylinder of one of the instruments the message to be 
transmitted is attached. ‘The message is written on tinfoil with a pen dipped in 
spirit varnish, which is sufficient to obstruct the passage of the electric current. On 
to the cylinder of the corresponding instrument the paper to receive the message is 
applied. It is moistened thoroughly with a solution which electricity will readily 
decompose, so that a mark may be made on the paper whenever the electric circuit 
is completed through it. : 
By this arrangement, as the metal style which presses on the written message 
passes over the unprotected tinfoil, the electric circuit is completed, and a blue line 
is drawn on the paper of the receiving instrament; but whenever the circuit is ‘in- 
terrupted by the varnish-writing a blank is left on the paper. In this manner, as 

