HENRY LAWRENCE EUSTIS. 517 



mathematical skill. They also require that they shall understand 

 the principles involved sufficiently well to solve the problems readily. 

 The different problems are written upon cards which are similar to 

 those used in library' catalogues. The correct solutions of the prob- 

 lems are written upon similar cards, and both the questions and the 

 answers are filed away in proper cases, and in the order in which they 

 are to be used. The Professor is accustomed to meet his classes for 

 several successive exercises, the number of them depending upon the 

 nature of the principles that are to be considered. During the-e 

 exercises he makes such explanations and suggestions as in his judg- 

 ment are necessary, in order that the students may understand this 

 entire subdivision of the subject, without questioning them often, but 

 always giving them an opportunity to question him. At the conclu- 

 sion of each of such a series of lectures, he hands some card of the 

 proper set to each student for solution. The solved answers enable 

 an accurate examination of the results obtained by the students to be 

 rapidly made. The promptness, certainty, and accuracy with which 

 all this is done are very noteworthy. It would be very greatly to the 

 advantage of students if this method of instruction should become 

 wide-spread, instead of exceptional." 



It would be beyond the scope of this notice to describe, or even to 

 enumerate, the problems upon the cards above mentioned, or the ad- 

 mii-able series of manuscript notes of which his students made such 

 liberal use. I have, however, thought it best to append the follow- 

 ing extracts from letters written by two of Professor Eustis's former 

 students, showing their affection for him as a man and their admiration 

 of him as a teacher. 



" In this busy community we often fail to express our appreciation 

 of the efforts and labors of those who have left us, havins finished 

 their work in this world. In expressing the debt I owe to Professor 

 Eustis, I am sure that I can also speak for scores of men in varied 

 pursuits, scattered over this continent, who will join with me in a 

 (jrateful and lovin"; tribute. 



•• Thirty years ago I came to Harvard University full of a desire 

 for a scientific education, albeit somewhat disheartened by never 

 having been stimulated by a great teacher. I shall never forget my 

 first recitation to Professor Eustis. Having learned my lesson and 

 delivered it in what I considered a perfect manner, I was surprised 

 by a sharp thrust from the gentlemanly man, with military yet 

 modest bearing, who presided over the section. This thrust com- 

 pletely demolished my superficial and egotistical structure, and showed 



