230 Notices respecting New Books. 



especially as thus extended in its application, cannot fail to 

 prove highly acceptable and useful to calculators, in the in- 

 terim, which I hope will not be a long one, before the four 

 remaining parts of this table are published, and also, all the fur- 

 ther arithmetical tables which Mr. Goodwyn has ready com- 

 puted. The ingenious calculator will be at no loss to perceive 

 an easy mode by help of the quarto pamphlet by Mr. G. en- 

 titled "The First Centenary," &c. announced in our 51st vo- 

 lume, as above, whereby any one amongst the very numerous 

 vulgar fractions, indicated above, may be sought for and found, 

 in tliis volume, and its equivalent decimal value obtained (by 

 aid of the circles) almost by inspection, to any desired number 

 of places of figui-es. 



Observations on the Effects of Lightning on Floating Bodies; 

 •with an Account of a ncno Method of applying Jixed and con- 

 tinuous Conductoi'-s of Electricity to the Masts of Ships. In a 

 Letter addressed to Vice-Admiral Sir Thomas Bi/cwi Martin, 

 K.C.B. Comptroller of His Majesti/s Naiy, S,-c. Src. Src. By 

 William Snow Harris, Member of the Royal College of Sur- 

 geons. Royal 4to. pp. 92. 



The nature of this work is very fully expressed in the title. 

 Though its principal object be the preservation of ships from 

 accidents by lightning — a most important subject — in other re- 

 spects it is well deserving of the attention of electricians, con- 

 taining many curious facts in their favourite branch of science. 

 Mr. Harris effects his object by inserting in a groove, ploughed 

 longitudinally in the aft part of the fixed and sliding masts, 

 slips of copper about an eighth of an inch thick and one inch 

 and a half wide, with an adequate metallic connexion in the 

 caps through which they slide, and a similar connexion with 

 the sea through the keel. The whole is so contrived, that any 

 elongation or contraction of the masts, or the removal of either 

 of them, will in no way break the continuity of the conductor. 

 The work is accompanied with five lithographic prints, and a 

 well-contrived experimental illustration of the course of the 

 lifT-hlning, effected by lines of gold (on paper) subjected to a 

 violent electrical discharge. 



Recent Publications. 

 An Epitome of the Elementary Principles of Natural and 

 Experimental Philosophy, including Mechanics, Pneumatics, 

 Acoustics, Hydrostatics, and Hydraulics ; with a copious Ac- 

 count of the Progress and present State of the Steam-Engine. 

 By John Millington, Prof. Mech. Royal Institution, Secre- 

 tary to the Astronomical Society, &c. 1 vol. 8vo. 1 1 Plates. 



The 



