16 Errors in the Nimtical Almanac. 



into. B, small conical vessels (as fig. 6.) for the purpose of 

 containing mercury, to insure the absolute contact of the wires 

 of the connecting rod c, which must be made of baked wood. 

 DD, wires for connecting tlie plates. E, the stand and adjust- 

 ing screw. 4. Glass plate and stand. 5. An apparatus for fixing 

 the conducting wires to, which will be found very useful. It 

 consists of the joint A, and two pieces of glass tube and platina 

 wires. Irwill also remove the inconvenience of holding'the wires. 

 Figs. 2. and 3. are longitudinal and transverse sections. 



It must appear very evident, that the above will form au 

 apparatus precisely similar to the coiironne des tasses of Volta, 

 when the rod c is let down. 



I do not pretend to say this would be an improvement ; but it 

 is an interesting question^ whether a battery on this plan would 

 not act with a greater promptitude. If after trial it should 

 not be found to possess any peculiar advantages, it will be at 

 least well adapted for the public lecturer, as his young hearers 

 will be enabled to form a better idea of the nature of Voltaic 

 electricitv. I ought, however, to state that I have not myself 

 had au opportunity of trying the arrangement Avhich I have sug- 

 gested. 



IV. Errors of Criticus Secundus in his Commvmcation 

 respecting the Nautical Almanac for 1813. 



To Mr. Tilloch. 



Sir, — i HAVE sincerely to entreat your forgiveness for having 

 myself committed an error in one part of my communication of 

 last month, concerning the errors in the Nautical Almanac for 

 the year 1815, where I have copied out the Trinity Sundays in 

 the two months that are ri<;;ht, instead of those that are wrong. 

 Thus we see that sometimes errors are catching. The only 

 reparation I can now make, is to announce the mistake, and 

 point out the correction, by observing that the numbers of the 

 Trinity Sundays in the two months of July and August are right 

 as printed in the Almanac, but that all those in the four months 

 June, September, October, November, as printed, are wrong, 

 being all one too little. 



I am, sir. 



Your humhle servant, 



July 11, 1814. CllITlCUS SeCUNDUS. 



V. An 



