MY SCHOOLS AND SCHOOLMASTERS. 331 



addresses you would undoubtedly be a different man from what be is. 

 His bone would have been different bone ; bis flesh different flesh — 

 nay, the very gray matter of his brain, which is said to be concerned 

 in the production of thought, would have been different from what it 

 now is. I wrote to Mr. Norris from the Alps asking him to choose be- 

 tween a purely scientific lecture and an address based on the experiences 

 of my own life. He chose the latter. I do not, however, ask you to 

 blame Mr. Norris, but to blame me, if a chapter from the personal his- 

 tory of a worker, instead of proving a stimulus and an aid, should seem 

 to you flat, stale, and unprofitable. . . . Speaking of the opportune 

 beneficence of Dr. Birkbeck's movement reminds me that, in the days 

 of my youth, personally and directly, I derived profit from that move- 

 ment. In 1842 and thereabout it was my privilege to be a member 

 of the Preston Mechanics' Institution — to attend its lectures and make 

 use of its library. One experiment made in these lectures I have never 

 forgotten — Surgeon Corless, I think it was, who lectured on respiration, 

 explaining, among other things, the changes produced by the passage of 

 air through the lungs. What went in as free oxygen came out bound 

 up in carbonic acid. To prove this he took a flask of lime-water, and, 

 by means of a glass tube dipped into it, forced his breath through the 

 water. The carbonic acid from the lungs seized upon the dissolved lime, 

 converting it into carbonate of lime, which, being jDractically insolu- 

 ble, was precipitated. All this was predicted beforehand by the lecturer, 

 but the delight with which I saw his prediction fulfilled, by the conver- 

 sion of the limpid lime-water into a turbid mixture of chalk and water, 

 remains with me, as a memory, to the present hour. The students of 

 the Birkbeck Institution may therefore grant me the honor of ranking 

 myself among them as a fellow-student of a former generation. At the 

 invitation of an ofiicer of the Royal Engineers, who afterward became 

 one of ray most esteemed and intimate friends, I quitted school in 

 1839 to join a division of the Ordinance Survey. The profession of a 

 civil engineer having then great attractions for me, I joined the survey, 

 intending, if possible, to make myself master of all its operations, as a 

 first step toward becoming a civil engineer. Draughtsmen were the 

 best paid, and I became a draughtsman. But I habitually made incur- 

 sions into the domains of the calculator and computer, and thus learned 

 all their art. In due time the desire to make myself master of field 

 operations caused me to apply for permission to go to the field. The 

 permission was granted by my excellent friend General George Wynne, 

 who then, as Lieutenant Wynne, observed and did all he coiild to pro- 

 mote my desire for improvement. Before returning to the office I had 

 mastered all the mysteries of ordinary field-work, and by a fortunate 

 opportunity, and with the sound knowledge of elementary geometry 

 and ti'igonometry which I had acquired before leaving school, was en- 

 abled successfully to make some trigonometrical observations, though 

 there had been bets against me. The pay upon the Ordinance Survey 



